Item 1. Business

ITEM 1. BUSINESS

General

As a global airline based in the United States, we connect customers across our expansive global network with a commitment to industry-leading customer service, safety and innovation. In 2023, we served over 190 million customers.

Competitive Advantages and Brand Strength

The competitive advantages that support our trusted consumer brand include our people and culture, operational reliability, global network, customer loyalty and financial foundation. In 2023, we continued to differentiate Delta from the industry by strengthening our competitive advantages.

People and Culture

The Delta people and culture are our strongest competitive advantage. Our more than 100,000 employees provide world-class travel experiences for our customers and best-in-class service, delivering customer satisfaction and brand preference. We believe that Delta's brand transcends the industry, powered by our people's outstanding work and passion for serving our customers. Delta is the world's No. 11 Most Admired Company as ranked by FORTUNE and is ranked No. 13 in the U.S. on Glassdoor's Best Places to Work list.

Our industry-leading profit sharing program directly aligns our employees' interests with the company's long-term success and for 2023, we are rewarding them with $1.4 billion in profit sharing payments. The company also maintains a Shared Rewards program to incentivize operational performance, and our employees earned $53 million under this program in 2023.

Operational Reliability

We remain committed to industry-leading reliability and are consistently among the industry's best performers, delivering the best on-time arrival among our network carrier peers in 2023. In recognition of our commitment to operational performance and minimizing passenger disruption, we were honored for the third consecutive year with the Cirium Platinum Award for global operational excellence in January 2024, and named the most on-time airline in North America. The Wall Street Journal named us the top airline of 2023 among the nine major U.S. airlines in its annual airline scorecard for the third consecutive year, leading the industry in on-time arrivals and involuntary denied boardings.

Global Network

We and our alliance partners collectively serve over 130 countries and territories and over 700 destinations around the world. At the end of 2023, we offered more than 4,000 daily flights to more than 280 destinations on six continents.

Our domestic network is centered around core hubs in Atlanta, Minneapolis-St. Paul, Detroit and Salt Lake City. Core hubs have strong local passenger share, a high penetration of customers loyal to Delta, a competitive cost position and strong margins. Core hub positions complement coastal hub positions in Boston, Los Angeles, New York-LaGuardia, New York-JFK and Seattle. Coastal hubs provide a strong presence in large revenue markets and enable growth in premium products and international service.

In 2023, we focused on restoring our core hubs while solidifying positions in our coastal hubs. We expect to leverage our coastal gateways and strategic relationships with international airline partners to further grow our international service.

Delta Air Lines, Inc. | 2023 Form 10-K 2

Item 1. Business

Internationally, we operate significant hubs in, or have market presence in the key cities of, Amsterdam, Bogota, Lima, London-Heathrow, Mexico City, Paris-Charles de Gaulle, Santiago (Chile), Sao Paulo, Seoul-Incheon and Tokyo. Through innovative alliances with Aeroméxico, LATAM Airlines Group S.A. ("LATAM"), Air France-KLM, China Eastern, Korean Air and Virgin Atlantic, we seek to bring more choice to customers worldwide. Our strategic relationships with these international airlines are an important part of our business as they improve our access to markets around the world and enable us to provide customers a more seamless global travel experience across our alliance network. The most significant of these arrangements are commercial joint ventures or cooperation agreements that include joint sales and marketing coordination, co-location of airport facilities and other commercial cooperation arrangements. In some cases, we have reinforced strategic alliances through equity investments where we have opportunity to create deep relationships and maximize commercial cooperation.

Our global network is supported by a fleet of 1,273 aircraft as of December 31, 2023 that are varied in size and capabilities, giving us flexibility to adjust aircraft to the network. We are continuing to refresh our fleet by acquiring new and more fuel-efficient aircraft with increased premium seating and cargo capacity to replace retiring aircraft. Simultaneously, we continue on our multi-year journey of fleet simplification by replacing retiring aircraft with deliveries of next-generation aircraft. In 2023, we took delivery of 43 aircraft, including new A321neos, A220-300s and A330-900s. Our new aircraft delivered since 2019 are on average 28% more fuel efficient per seat mile than aircraft retired since 2019. In January 2024, we entered into a purchase agreement with Airbus for 20 A350-1000 aircraft, with an option to purchase an additional 20 widebody aircraft. Deliveries of these aircraft are scheduled to begin in 2026.

Customer Loyalty

With operational excellence, best-in-class service and commitment to our customers, we have continued to earn our customers' trust and preference by delivering the "Delta Difference." We are elevating the customer experience by deploying our newest aircraft, accelerating generational airport investments in key markets, including new facilities that opened at New York-LaGuardia, Los Angeles and Salt Lake City, and investing in our digital transformation. We believe our continued investment in customer service and experience, operations, product, airports and technology has shaped customer perception of our brand leading to improvements in our domestic net promoter scores and increased customer loyalty compared to pre-pandemic levels. In 2023, various outlets recognized Delta as a trusted consumer brand, including:

• Named the number one airline by corporate travel customers in the annual Business Travel News Airline Survey for the 13th year in a row and the number one U.S. airline by Condé Nast Traveler readers.

• Ranked No. 12 in TIME magazine's World's Best Companies of 2023 based on revenue growth, employee satisfaction and the company's sustainability profile.

• Earned the No. 1 spot on The Points Guy's list of best U.S. Airlines for the fifth year in a row, and USA Today readers selected Delta as the Best Airline of 2023.

Our award-winning SkyMiles program, discussed in further detail below, is designed to attract lifetime members and to grow customer loyalty by offering our customers a wide variety of benefits when traveling with us and our partners, and personalizing our engagement with them. We aim to increase the value of our program for customers and to deepen customer engagement with Delta through a growing ecosystem of partnerships with premier brands, extending the value of our SkyMiles currency beyond flight and introducing new technology initiatives. We believe there is opportunity to continue this trend and expect the increased value we provide customers to deliver high-margin revenue and resilient cash flows.

Financial Foundation

In 2023, we made significant progress restoring our financial foundation with strong profitability and $2 billion of free cash flow for the year. Our financial results are discussed in more detail in "Item 7. Management's Discussion and Analysis," which includes definitions and reconciliations of non-GAAP financial measures, including free cash flow, under the "Supplemental Information" section.

Restoring the strength of our balance sheet and reducing debt is a key financial priority. During 2023, we repaid approximately $4.1 billion in debt and finance lease obligations and the company remains committed to regaining investment grade metrics.

Delta Air Lines, Inc. | 2023 Form 10-K 3

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Over the last decade we have fundamentally transformed our business by investing in our people, our product and our reliability to alter the commodity-like nature of air travel and improve our financial foundation. We have diversified our business by growing high-margin revenue streams that leverage our competitive advantages, including:

• Our continued focus on our premium products (including Delta One®, First Class, Delta Premium Select and Delta Comfort+®) and customer segmentation, which has reduced our reliance on the most price sensitive customer segment.

• Our partnership with American Express, which provides us a co-brand revenue stream tied to broader consumer spending.

• Our Maintenance, Repair and Overhaul ("MRO") operation, where we believe that we remain well-positioned for growth through contractual agreements with jet engine manufacturers, including three next generation engine platforms.

• Our other complementary portfolio businesses, such as our cargo business and our travel-adjacent services, which include trip insurance, car and hotel rentals.

Our premium yield growth has significantly outpaced main cabin, with record paid load factors in premium cabin in 2023, as demand for premium products continues to grow. In 2023, we grew our mix of premium seats, including the continued expansion of Delta Premium Select. The sale of premium products is facilitated through various distribution channels, with 62% of tickets sold through direct channels in 2023. These include digital channels, such as the Fly Delta app, which surpassed one billion visits in 2023, delta.com and our reservations specialists. Indirect distribution channels include online travel agencies and traditional "brick and mortar" agencies. We make fare and product information widely available across those channels in an effort to ensure customers receive the best information and service options, further supporting the growth of premium products.

SkyMiles Program

Our SkyMiles program provides members with the ability to earn mileage credits ("miles") when traveling on Delta, Delta Connection and our partner airlines. Miles may also be earned by using certain services offered by program partners, such as credit card, retail, ridesharing, car rental and hotel companies. To facilitate transactions with participating companies, we sell miles to non-airline businesses and other airlines.

Miles may be used toward award redemptions such as flights and upgrades on Delta, our regional carriers and other participating airlines as well as donations to specific charities and more. In 2023, 10% of revenue miles flown on Delta were from award travel, as program members redeemed miles in the loyalty program for approximately 30 million award tickets. Our most significant and valuable contract to sell miles relates to our co-brand credit card relationship with American Express. In 2023, remuneration from American Express totaled $6.8 billion, which we expectto increase by 10% in 2024 and grow to $10 billion over the long-term.

Innovative Investments in Technology

Our objective is to make technology a strategic differentiator. We continue to invest in technological improvements that enhance the customer experience, support our operations and empower our people. These investments include innovations to customer facing applications and improvements to infrastructure and technology architecture to unify and improve access to data sources. We believe this digital transformation enhances interactions with our customers and allows our people to deliver more personalized service, further enhancing the customer experience, strengthening our brand and driving revenue and efficiency.

Through the development of innovative new technologies, we can better serve customers and give our employees the best tools. For our customers, we are making investments in the digital platforms on the ground and in the air. We continue to evolve the Fly Delta app into a digital travel concierge for our customers to offer convenient services on the day of travel and deliver thoughtful notifications to make their travel journeys more seamless. On the ground, we are investing to create a smoother, less stressful and increasingly contactless travel experience. Onboard the aircraft, we continue to invest in in-flight entertainment and announced fast and free Wi-Fi for all customers through a free SkyMiles account on most domestic mainline flights, with plans for full availability on international and regional aircraft. We also introduced Delta Sync, which will enable the creation of more personalized experiences over the next several years and further elevate the consumer experience across the travel journey, including partnerships with leading brands. For our employees, we are investing in applications that allow our people to have more meaningful interactions with our customers.

Delta Air Lines, Inc. | 2023 Form 10-K 4

Item 1. Business

Commercial Arrangements with Other Airlines

Joint Venture/Cooperation Agreements. We have implemented four separate joint venture or joint cooperation agreements with foreign carriers as described below. We have sought to reinforce a number of the agreements through equity investments in those carriers. See Note 4 of the Notes to the Consolidated Financial Statements for additional information about our equity investments.

Each of our joint venture or cooperation arrangements provides for joint commercial cooperation with the relevant partner within the geographic scope of the arrangement, including the sharing of revenues and/or profits and losses generated by the parties on the joint venture routes, as well as joint marketing and sales, coordinated pricing and revenue management, network and schedule planning and other coordinated activities with respect to the parties' operations on joint venture routes. Our implemented commercial joint ventures/cooperation agreements consist of the following:

• A combined joint venture with Air France, KLM and Virgin Atlantic with respect to transatlantic traffic flows. In addition to the joint venture, we own a non-controlling 49% equity stake in Virgin Atlantic Limited, the parent company of Virgin Atlantic Airways and a 3% ownership stake in the parent company of Air France and KLM.

• A joint cooperation agreement with Aeroméxico with respect to trans-border traffic flows between the U.S. and Mexico. In addition to the joint cooperation agreement, we currently own an approximately 20% equity stake in Grupo Aeroméxico, S.A.B. de C.V., the parent company of Aeroméxico.

• A joint venture agreement with LATAM with respect to traffic flows between North and South America, allowing our passengers to access more than 300 destinations between the United States/Canada and South America (Brazil, Chile, Colombia, Paraguay, Peru and Uruguay). We currently own an approximately 10% equity stake in LATAM.

• A joint venture with Korean Air with respect to traffic flows between the United States and certain countries in Asia. In addition to the joint venture, we own just under 15% of the outstanding common stock of Hanjin-KAL, the largest shareholder of Korean Air.

Each of our joint venture or joint cooperation agreements described above has been approved and granted antitrust immunity from the U.S. Department of Transportation ("DOT"). The grant of antitrust immunity for our joint cooperation agreement with Aeroméxico is subject to a pending renewal application with the DOT, which was tentatively dismissed pursuant to an Order to Show Cause issued by the DOT on January 26, 2024. The existing immunity remains in effect pending final adjudication of the renewal application, the timing and outcome of which cannot be predicted at this time.

Enhanced Commercial Agreements with China Eastern. We own a 2% equity interest in China Eastern, with whom we have a strategic joint marketing and commercial cooperation arrangement covering traffic flows between China and the U.S., which includes reciprocal codesharing, loyalty program participation, airport lounge access and joint sales cooperation.

SkyTeam. We are a member of the SkyTeam global airline alliance. The other members of SkyTeam are Aerolíneas Argentinas, Aeroméxico, Air Europa (Spain), Air France, China Airlines, China Eastern, Czech Airlines, Garuda Indonesia, ITA Airways (Italy), Kenya Airways, KLM, Korean Air, Middle East Airlines, Saudia, TAROM (Romania), Vietnam Airlines, Virgin Atlantic and Xiamen Airlines (China). Through alliance arrangements with other SkyTeam carriers, we are able to link our route network with those of the other member airlines, providing opportunities to increase connecting traffic while offering enhanced customer service through reciprocal codesharing and loyalty program participation, airport lounge access and cargo operations.

Other International Carriers. We also have marketing arrangements with other airlines to enhance our global network. These arrangements may include codesharing, reciprocal loyalty program benefits, shared or reciprocal access to passenger lounges, joint promotions, common use of airport gates and ticket counters, office co-location and other activities.

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Regional Carriers

We have air service agreements with domestic regional air carriers that feed traffic to our network by serving passengers primarily in small and medium-sized cities in the domestic market. These arrangements enable us to better match capacity with demand in these markets.

Through our regional carrier program, Delta Connection®, we have contractual arrangements with regional carriers to operate aircraft using our "DL" designator code. We currently have contractual arrangements with:

• Endeavor Air, Inc., a wholly owned subsidiary of ours ("Endeavor").

• Republic Airways, Inc.

• SkyWest Airlines, Inc. ("SkyWest Airlines").

Our contractual agreements with regional carriers are primarily capacity purchase arrangements, under which we control the scheduling, pricing, reservations, ticketing and seat inventories for the regional carriers' flights operating under our "DL" designator code. We are entitled to all ticket, cargo, mail, in-flight and ancillary revenues associated with the flights under these capacity purchase arrangements. We pay those airlines an amount, as defined in the applicable agreement, which is based on a determination of their cost of operating those flights and other factors intended to approximate market rates for those services. These capacity purchase agreements are long-term agreements, usually with initial terms of at least ten years, which grant us the option to extend the initial term. Certain of these agreements provide us the right to terminate the entire agreement, or in some cases remove some of the aircraft from the scope of the agreement, for convenience at certain future dates.

SkyWest Airlines operates some flights for us under a revenue proration agreement. This proration agreement establishes a fixed dollar or percentage division of revenues for tickets sold to passengers traveling on connecting flight itineraries.

Cargo

Through our global network, our cargo operations are able to connect the world’s major freight gateways. We generate cargo revenues in domestic and international markets through the use of cargo space on regularly scheduled passenger aircraft. We are a member of SkyTeam Cargo, an international airline cargo alliance with eight other airlines that offer a network spanning six continents, through which we provide global solutions to our customers by connecting our network with those partners.

In 2023, cargo revenues decreased year over year, mostly resulting from lower yield due to decreased market demand and increased industry capacity.

Other Complementary Businesses

We have various other businesses arising from our airline operations, including the following:

• In addition to providing maintenance and engineering support for our fleet of 1,273 mainline and regional aircraft, our MRO operation, known as Delta TechOps, serves aviation and airline customers from around the world. With agreements to service multiple next-generation aircraft engines, Delta TechOps is positioned as a leading global service provider for state-of-the-art, more sustainable engines.

• Our vacation wholesale subsidiary, Delta Vacations, provides vacation packages to third-party consumers. Revenue allocated to Delta Vacations excludes flight revenue associated with vacation packages.

In 2023, the aggregate revenue from our MRO operation and Delta Vacations was approximately $840 million.

Delta Air Lines, Inc. | 2023 Form 10-K 6

Item 1. Business

Environmental Sustainability

In 2023, we outlined our roadmap to a more sustainable future of travel that details our strategy for achieving net-zero greenhouse gas emissions from our airline operations by 2050. As part of this roadmap, we announced short-, medium- and long-term milestones which will help us measure and report progress towards our ultimate net-zero goal. In 2023, we made progress toward achievement of our goals across three key areas:

What We Fly

• Fleet renewal: We continue to make our existing fleet more efficient as older aircraft are retired. Additions to our fleet since 2019, including 43 new aircraft delivered in 2023, are on average 28% more fuel efficient per seat mile than aircraft retired since 2019. We also completed the retirement of the CRJ-200 fleet in 2023, our least fuel-efficient aircraft type, contributing to a fleet-wide fuel efficiency improvement of 5.5% compared to 2019.

• Pursuing future aviation technologies: Our sustainability strategy aims to introduce revolutionary aircraft into our fleet. In 2023, we joined a coalition alongside Boeing and NASA to support the Sustainable Flight Demonstrator program. We will serve as an adviser on a new aircraft design with a Transonic Truss-Braced Wing, which will be the first ever experimental aircraft focused on sustainability. We sold two retired MD-90 aircraft to Boeing which will become the test planes for the program. This innovative project supplements previously announced partnerships with Airbus on their hydrogen-powered aircraft research as well as our investment in Joby Aviation, which aims to pioneer home-to-airport transportation through electric, vertical takeoff and landing (eVTOL) technology.

• Fleet modification: Following the completed installation of split-scimitar winglets on the Boeing 737-900ER fleet, and outfitting all Boeing 737-800 and 737-900ER aircraft with lighter-weight, radial landing gear tires in 2022, we began installing split-scimitar winglets on the 737-800 fleet in 2023. When complete, this enhancement is expected to drive approximately three million gallons of fuel savings annually. Additionally, we completed modifications and certification test flights for a novel drag reduction system on the 737-800 fleet with Aero Design Labs, accelerating the certification of this innovation.

How We Fly

• Aircraft operations: Teams across Delta have worked together to make an impact through enhanced landing procedures, optimizations to flight routing and speed, and weight reduction initiatives. These cross-divisional efforts coordinated through our Carbon Council have saved over 20 million gallons of jet fuel in 2022 and 2023.

• Waste reduction: Our Waste Council was established in 2023 and led the evaluation of test sites across our operation aiming to capture more recyclable materials by changing processes and leveraging catering kitchens. We also launched our paperless gates initiative in 2023, allowing gate agents to bypass the automatic printing of pre-departure and departure documents on all flights. The effort eliminates printer malfunctions, cuts paper and printer maintenance costs and saves an estimated 70 million pages per year – the equivalent to 4,000 trees.

• Ground operations: In 2023, we purchased more than 500 new electric ground support equipment ("GSE") for utilization across our network, inclusive of baggage tractors, belt loaders, and aircraft tow tractors. The equipment necessary to turn an aircraft (core GSE) at our hubs in Salt Lake City and Boston is nearly entirely powered with electricity.

The Fuel We Use

• Continued investment in sustainable aviation fuel ("SAF"): With approximately 90% of our carbon emissions coming from jet fuel, finding lower emissions fuel alternatives is critical to making progress toward net zero. SAF, which can be channeled to airports through existing fuel infrastructure, is central to reducing the lifecycle emissions from aviation fuel and is safe to use in current aircraft engines. Our Global Sustainability and Fuel teams have been working over the past several years to catalyze investment and stimulate SAF production by signing offtake agreements with various SAF producers. Under these agreements, we have contracted to purchase SAF when it is available, subject to certain conditions. In 2023, we used over three million gallons of SAF onboard our aircraft, nearly doubling our 2022 SAF utilization.

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Item 1. Business

• Building coalitions for the future: We continue to advocate for policy incentives to scale the SAF market. For example, we are a founding member of Americans for Clean Aviation Fuels (ACAF), a diverse coalition of the largest industrial sectors in America from farmers to fuel producers and aviation to agribusiness. This coalition is focused on promoting the economic benefits of building a robust market for SAF and clean aviation fuels. We are also a founding member of the Minnesota SAF Hub, a first-of-its-kind partnership among corporations seeking to collaborate on scaling SAF production.

The global aviation industry is viewed as a "hard-to-abate" sector, meaning it is innately difficult to decarbonize. Achieving our long-term goals will require substantial expansion of the SAF market, the adoption of new technologies, engagement from both internal and external stakeholders, as well as partnerships across industries to increase production of alternative fuels and help drive down costs.

Employee Matters

Human Capital and Commitment to Diversity, Equity and Inclusion

We believe that the Delta people and culture are our strongest competitive advantage, and the high-quality service that our employees provide sets us apart from other airlines. As of December 31, 2023, we had approximately 103,000 full-time employee equivalents, of which approximately 100,000 were based in the U.S.

Our principal human capital management objectives are to attract, retain and develop people who understand and are committed to delivering the "Delta Difference" that is core to our brand. To support these objectives, we have put in place programs that seek to:

• Reward our people through highly competitive total compensation designed to share Delta’s success with our employees who make it possible and promote teamwork and collaboration across the business.

• Achieve high performance by fostering our people’s holistic wellbeing including physical, emotional, social and financial wellbeing.

• Drive employees’ professional and community engagement.

• Prepare our employees for key roles and future leadership positions through a variety of training and development programs.

• Enhance our culture through efforts aimed at making our workplace more engaging, equitable and inclusive.

The health and safety of our employees is foundational to achieving these objectives. Delta's Safety Management System is central to promoting a positive safety culture, proactively managing safety risk, and making investments to ensure a safe experience for our employees and customers.

Our commitment to diversity, equity and inclusion is critical to effective human capital management at Delta. As a global airline, we are in the business of bringing people together, and we believe our business should reflect the diversity of our customer base. To achieve this goal, we seek diverse talent internally and externally in an effort to achieve broader representation throughout our organization. We also promote inclusion through education, training and development opportunities as well as by leveraging insights from our ten employee resource groups, which we refer to as business resource groups, totaling membership of more than 30,000 as of December 31, 2023.

We continued to invest in our leadership’s equity learning and understanding in 2023, with nearly 80% of officers participating in our voluntary two-day racial equity workshop by the end of 2023. In 2023, we also introduced a new diversity, equity and inclusion education program, building on foundational learnings through a multitude of different training offerings.

In addition, we are reviewing and revising systems, practices and policies in support of our commitment to diversity, equity and inclusion and with a focus on achieving equitable outcomes. Two key areas on which we are focused are (1) reinforcement of our diverse talent pipeline by, among other things, requiring hiring candidate slates and interview panels to reflect diversity, and taking a proactive approach to build internal and external career pathways to certain roles by removing college degree requirements and introducing a skills-first talent approach, and (2) closing diversity gaps in senior leadership positions by increasing the representation of women, Black and Latin/Hispanic groups in those roles.

Delta Air Lines, Inc. | 2023 Form 10-K 8

Item 1. Business

We also believe that listening, engaging and connecting with employees furthers our human capital management objectives. We have historically done so primarily through our open-door policy, digital communication across all levels of the company, in-person events with senior management and company-wide and division-specific surveys to evaluate employee satisfaction. Members of senior management participate in regular company-wide town hall discussions with our employees and our senior executive leadership team regularly shares memos with all employees regarding our ongoing commitment to our people and our culture. We have also continued to conduct periodic employee surveys to seek feedback on engagement levels in general, our wellbeing programs, diversity, equity and inclusion efforts and our culture of safety.

Collective Bargaining

As of December 31, 2023, approximately 20% of our full-time equivalent employees were represented by unions.

Domestic airline employees represented by collective bargaining agreements by group

Employee Group

Approximate Number of Employees Represented

Union

Date on which Collective Bargaining Agreement Becomes Amendable

Delta Pilots(1)

16,960

ALPA

December 31, 2026

Delta Flight Superintendents (Dispatchers)

490

PAFCA

November 1, 2024

Endeavor Pilots

1,530

ALPA

January 1, 2029

Endeavor Flight Attendants

1,600

AFA

March 31, 2027

(1) Delta’s pilots ratified a new four-year Pilot Working Agreement in March 2023, effective January 1, 2023.

In addition to the domestic airline employee groups discussed above, approximately 200 refinery employees of our wholly owned subsidiary, Monroe Energy, LLC ("Monroe") are represented by the United Steel Workers under an agreement that expires on February 28, 2026. This agreement is governed by the National Labor Relations Act ("NLRA"), which generally allows either party to engage in self-help upon the expiration of the agreement. Certain of our employees outside the U.S. are represented by unions, work councils or other local representative groups.

Labor unions periodically engage in organizing efforts to represent various groups of our employees, including at our operating subsidiaries, that are not represented for collective bargaining purposes.

Fuel

Our results of operations are significantly impacted by changes in the price and availability of aircraft fuel. We purchase most of our aircraft fuel under contracts that establish the price based on various market indices and therefore do not provide material protection against price increases or assure the availability of our fuel supplies. We also purchase aircraft fuel on the spot market, from offshore sources and under contracts that permit the refiners to set the price. We are currently able to obtain adequate supplies of aircraft fuel, including fuel produced by Monroe or procured through the exchange of gasoline, diesel and other refined petroleum products ("non-jet fuel products") the refinery produces, and crude oil for Monroe's operations.

The following table shows our aircraft fuel consumption and costs:

Fuel consumption and expense by year
Year	Gallons Consumed(1) (in millions)	Cost(1)(2) (in millions)		Average Price Per Gallon(1)(2)		Percentage of Total Operating Expense(1)(2)
2023	3,926	$	11,069	$	2.82	21	%
2022	3,412	$	11,482	$	3.36	24	%
2021	2,778	$	5,633	$	2.02	20	%

(1)Includes the operations of our regional carriers operating under capacity purchase agreements.

(2)Includes the impact of fuel hedge activity and refinery segment results.

Delta Air Lines, Inc. | 2023 Form 10-K 9

Item 1. Business

Monroe Energy

Our Monroe subsidiaries operate the Trainer refinery and related logistics assets located near Philadelphia, Pennsylvania. The facilities include pipelines and terminal assets that allow the refinery to supply jet fuel to our airline operations throughout the Northeastern U.S., including our New York hubs at LaGuardia and JFK. These companies are distinct from us, operating under their own management teams and with their own boards. We own Monroe as part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel, as well as to maintain sufficiency of supply to our New York operations.

Refinery Operations. The facility is capable of refining approximately 200,000 barrels of crude oil per day and sources domestic and foreign crude oil supply from a variety of providers. During 2023, Monroe successfully performed a planned plant-wide maintenance turnaround ("turnaround"), which addressed all required inspections, allowed Monroe to clean and repair all of the equipment, as well as enable the installation of a new Fluidized Catalyst Cracking Unit Reactor.

Strategic Agreements. Monroe has agreements in place to exchange the non-jet fuel products the refinery produces with third parties for jet fuel consumed in our airline operations.

Environmental Sustainability. Delta is evaluating operational pathways for integrating Monroe into Delta's net zero future. Monroe’s sustainability ambitions include being one of the most energy efficient refineries in the country with the lowest energy intensity and greenhouse gas ("GHG") emissions on an absolute and per barrel basis. For example, Monroe is implementing a plan to replace steam driven turbines that currently power pumps at the facility with more efficient and reliable electric motors, which will reduce the amount of steam required from the facility’s natural gas-fired boilers. Monroe is also recovering and utilizing methane, a potent GHG, instead of flaring it into the atmosphere. Finally, in support of Delta’s 10% SAF goal, Monroe is evaluating the possibility of producing SAF and other renewable fuels at the Trainer refinery, although additional analyses must be conducted to determine economic and operational viability of various SAF production pathways. Monroe continues to evaluate the production of renewables, and in 2023 successfully produced a test quantity of renewable diesel at the facility.

Fuel Hedging Program

Our derivative contracts to hedge the financial risk from changing fuel prices are related to Monroe’s inventory. We may utilize different contract and commodity types in this program and frequently test their economic effectiveness against our financial targets. We closely monitor the hedge portfolio and rebalance the portfolio based on market conditions, which may result in locking in gains or losses on hedge contracts prior to their settlement dates.

Competition

The airline industry is highly competitive, marked by significant competition with respect to routes, fares, schedules (both timing and frequency), operational reliability, services, products, customer service and loyalty programs. The industry has evolved through mergers, new entries, both domestically and internationally, and changes in international alliances. Consolidation in the airline industry, the presence of subsidized government-sponsored international carriers, changes in international alliances and the creation of immunized joint ventures have altered, and will continue to alter, the competitive landscape in the industry, resulting in the formation of airlines and alliances with significant financial resources, extensive global networks and competitive cost structures.

Domestic

Our domestic operations are subject to significant competition from traditional network carriers, including American Airlines and United Airlines, national point-to-point carriers, including Alaska Airlines, JetBlue Airways and Southwest Airlines, and other discount or ultra-low-cost carriers, including Allegiant Air, Avelo Airlines, Breeze Airways, Frontier Airlines and Spirit Airlines. Some of these carriers have business models primarily focused on maintaining low costs, with the intention of providing service at lower fares to destinations served by Delta. In particular, we face significant competition at our domestic hubs and key airports either directly at those airports or at the hubs of other airlines that are located in close proximity. We also face competition in small- to medium-sized markets from regional jet operations of other carriers.

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International

Our international operations are subject to competition from both foreign and domestic carriers, including from point-to-point carriers on certain international routes. Through alliance and other marketing and codesharing agreements with foreign carriers, U.S. carriers have increased their ability to sell international transportation, such as services to and beyond traditional European, Asian and Latin American gateway cities. Similarly, foreign carriers have obtained increased access to interior U.S. passenger traffic beyond traditional U.S. gateway cities through these relationships.

In particular, several joint ventures among U.S. and foreign carriers, including several of our joint ventures as well as those of our competitors, have received grants of antitrust immunity allowing the participating carriers to coordinate networks, schedules, pricing, sales and inventory. In addition, alliances formed by domestic and foreign carriers, including SkyTeam, the Star Alliance (among United Airlines, Lufthansa German Airlines, Air Canada and others) and the oneworld alliance (among American Airlines, British Airways, Qantas and others) have enhanced competition in international markets.

Regulatory Matters

The DOT and the Federal Aviation Administration (the "FAA") exercise regulatory authority over air transportation in the U.S. The DOT has authority to issue certificates of public convenience and necessity required for airlines to provide air transportation. An air carrier that the DOT finds fit, willing and able to perform the proposed service is given authority to operate domestic and international air transportation (including the carriage of passengers and cargo), as applicable. Since the passage of the Airline Industry Deregulation Act in 1978, airlines have generally been free to launch or terminate service to U.S airports without restriction, except with respect to certain slot-controlled and schedule-facilitated airports, as well as certain constraints related to service to small communities governed by the "Essential Air Services" program.

The DOT has jurisdiction over certain economic and consumer protection matters, such as unfair or deceptive practices and methods of competition, advertising, denied boarding compensation, baggage liability and disabled passenger transportation. The DOT also has authority to review certain joint venture agreements between domestic and international carriers. The DOT engages in regulation of economic matters such as transactions involving allocation of "slots" or similar regulatory mechanisms which limit the rights of carriers to conduct operations at airports where such mechanisms are in place. The FAA has primary responsibility for matters relating to the safety of air carrier flight operations, including airline operating certificates, control of navigable air space, flight personnel, aircraft certification and maintenance and other matters affecting air safety.

Authority to operate international routes and international codesharing arrangements is regulated by the DOT and by the governments of the foreign countries involved. International certificate authorities are also subject to the approval of the U.S. President for conformance with national defense and foreign policy objectives.

The Transportation Security Administration ("TSA") and the U.S. Customs and Border Protection, each a division of the Department of Homeland Security, are responsible for certain civil aviation security matters, including passenger and baggage screening at U.S. airports and international passenger prescreening prior to entry into or departure from the U.S.

Airlines are also subject to various other federal, state, local and foreign laws and regulations. For example, the U.S. Department of Justice has jurisdiction over some airline competition matters. The U.S. Postal Service has authority over certain aspects of the transportation of mail. Labor relations in the airline industry, as discussed below, are generally governed by the Railway Labor Act with oversight by the National Mediation Board ("NMB"). Environmental matters are regulated by various federal, state, local and foreign governmental entities. Privacy of passenger and employee data is regulated by domestic and foreign laws and regulations.

Fares and Rates

Airlines set ticket prices in all domestic and most international city-pairs with minimal governmental regulation, and the industry is characterized by significant price competition. Certain international fares and rates are subject to the jurisdiction of the DOT and the governments of the foreign countries involved. Many of our tickets are sold by travel agents, and fares are subject to commissions, overrides and discounts paid to travel agents, brokers and wholesalers.

Delta Air Lines, Inc. | 2023 Form 10-K 11

Item 1. Business

Route Authority

Our flight operations are authorized by certificates of public convenience and necessity and also by exemptions and limited-entry frequency awards issued by the DOT. The requisite approvals of other governments for international operations are controlled by bilateral agreements (and a multilateral agreement in the case of the U.S. and the European Union ("EU")) with, or permits or approvals issued by, foreign countries. Because international air transportation is governed by bilateral or other agreements between the U.S. and the foreign country or countries involved, changes in U.S. or foreign government aviation policies could result in the alteration or termination of such agreements, diminish the value of our international route authorities or otherwise affect our international operations. Bilateral agreements between the U.S. and various foreign countries that we serve are subject to renegotiation from time to time. The U.S. government has negotiated "Open Skies" agreements with many countries, which allow unrestricted access between the U.S. and these foreign markets.

Certain of our international route authorities are subject to periodic renewal requirements. We request extension of these authorities when and as appropriate. While the DOT usually renews temporary authorities on routes where the authorized carrier is providing a reasonable level of service, there is no assurance this practice will continue in general or with respect to a specific renewal. Dormant route authorities may not be renewed in some cases, especially where another U.S. carrier indicates a willingness to provide service.

Airport Access

Operations at three major domestic airports and certain foreign airports that we serve are regulated by governmental entities through allocations of "slots" or similar regulatory mechanisms. Each slot represents the authorization to land at or take off from the particular airport during a specified time period.

In the U.S., the FAA currently regulates the allocation of slots, slot exemptions, operating authorizations or similar capacity allocation mechanisms at Reagan National in Washington, D.C. and LaGuardia and JFK in the New York City area. Our operations at these airports generally require the allocation of slots or analogous regulatory authorizations. Similarly, our operations at London's Heathrow airport, Tokyo's Haneda airport and other international airports are regulated by local slot coordinators pursuant to the International Air Transport Association's Worldwide Scheduling Guidelines and applicable local law. We currently have sufficient slots or analogous authorizations to operate our existing flights, and we have generally been able to obtain the rights to expand our operations and to change our schedules. There is no assurance, however, that we will be able to do so in the future because, among other reasons, such allocations are subject to changes in governmental policies.

Airline Labor Regulation

In the U.S., airlines and labor unions are governed by the Railway Labor Act. Under the Railway Labor Act, a labor union seeking to represent an unrepresented craft or class of employees is required to file with the NMB an application alleging a representation dispute, along with authorization cards signed by at least 50% of the employees in that craft or class. The NMB then investigates the dispute and, if it finds the labor union has obtained a sufficient number of authorization cards, conducts an election to determine whether to certify the labor union as the collective bargaining representative of that craft or class. A labor union will be certified as the representative of the employees in a craft or class if more than 50% of votes cast are for representation. A certified labor union would then commence negotiations toward a collective bargaining agreement with the employer.

Under the Railway Labor Act, a collective bargaining agreement between an airline and a labor union does not expire, but instead becomes amendable as of a stated date. Either party may request that the NMB appoint a federal mediator to participate in the negotiations for a new or amended agreement. If no agreement is reached in mediation, the NMB may determine, at any time, that an impasse exists and offer binding arbitration. If either party rejects binding arbitration, a 30-day "cooling off" period begins. At the end of this 30-day period, the parties may engage in "self-help," unless the U.S. President appoints a Presidential Emergency Board ("PEB") to investigate and report on the dispute. The appointment of a PEB maintains the "status quo" for an additional 60 days. If the parties do not reach agreement during this period, the parties may then engage in self-help. Self-help includes, among other things, a strike by the union or the imposition of proposed changes to the collective bargaining agreement by the airline. The U.S. Congress and the President have the authority to prevent self-help by enacting legislation that, among other things, imposes a settlement on the parties.

Delta Air Lines, Inc. | 2023 Form 10-K 12

Item 1. Business

Environmental Regulation

Environmental Compliance Obligations. Our operations are subject to numerous international, federal, state and local laws and regulations governing protection of the environment, including regulation of greenhouse gases and other air emissions, noise reduction, water discharges, aircraft drinking water, storage and use of petroleum products and other regulated substances, and the management and disposal of hazardous waste, substances and materials.

We are also subject to certain environmental laws and contractual obligations governing the management and release of regulated substances, which may require the investigation and remediation of affected sites. Soil and/or ground water impacts have been identified at certain of our current or former leaseholds at several domestic airports. To address these impacts, we have a program in place to investigate and, if appropriate, remediate these sites. Although the ultimate outcome of these matters cannot be predicted with certainty, we believe that the resolution of these matters will not have a material adverse effect on our Consolidated Financial Statements.

In 2022, the U.S. Environmental Protection Agency (the "EPA") proposed regulations to define certain per- and polyfluoroalkyl substances ("PFAS") as "hazardous substances" under the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), and the EPA has proposed to regulate certain PFAS as "hazardous constituents" under the Resource Conservation and Recovery Act ("RCRA"). The EPA is also proposing to regulate PFAS under the Safe Drinking Water Act. PFAS are used in a wide variety of consumer and industrial products, including the firefighting foams used to extinguish fuel-based fires at airports and refineries. Numerous states have adopted regulations governing PFAS as well, and some have adopted legislation prohibiting the manufacture, sale, distribution and/or use of firefighting foam containing intentionally added PFAS. The EPA’s proposed rule under CERCLA, once finalized, could subject airports, airlines, and refineries, among others, to potential liability for cleanup of historical PFAS contamination associated with use of PFAS-containing firefighting foam, and some state laws require transition to alternative fire suppression systems. To address these possibilities, Delta is developing plans to transition its aircraft maintenance hangars to systems that do not contain intentionally added PFAS. The ultimate impact and associated cost to Delta of these legislative and regulatory developments cannot be predicted at this time.

GHG Emissions. Aviation industry GHG emissions, particularly carbon emissions, and their impact on climate change have become a focus in the international community and within the U.S. In 2016, the International Civil Aviation Organization ("ICAO") formally adopted a global, market-based emissions offset program known as the Carbon Offsetting and Reduction Scheme for International Aviation ("CORSIA"). This program establishes a goal for the aviation industry to achieve carbon-neutral growth in international aviation beginning in 2021. Any growth above the baseline would need to be addressed using either eligible carbon offsets or a lower carbon fuel. ICAO set the baseline for establishing airlines’ obligations under CORSIA for 2021 to 2023 based on 2019 travel, and in 2022 set a new, more stringent CORSIA baseline of 85% of 2019, which will apply from 2024 through 2035.

The pilot phase of the CORSIA program ran from 2021 through 2023, and is being followed by a first phase of the program beginning in 2024 and a second phase beginning in 2027. Countries can voluntarily participate in the pilot and first phase, and the United States agreed to participate in these voluntary phases. Participation in the second phase is mandatory for certain countries, including the United States. The U.S. government has not yet enacted legislation to mandate that U.S. operators participate in CORSIA. Nonetheless, we have voluntarily submitted verified emissions reports on our annual international emissions. While airlines had no offsetting obligations during the pilot phase of CORSIA as a result of the impact of the COVID-19 pandemic on international travel, we expect that international airline emissions will likely exceed the new baseline during the next phase (2024 – 2026). Because certain CORSIA program details remain to be developed and could potentially be affected by political developments in participating countries or the results of the initial phases of the program, the impact of CORSIA cannot be predicted at this time. However, CORSIA is expected to increase operating costs for airlines that operate internationally.

Additionally, the EU requires its member states to implement regulations to include aviation in its Emissions Trading Scheme ("ETS"). Under these regulations, any airline with flights originating or landing in the European Economic Area ("EEA") is subject to the ETS and, beginning in 2012, was required to purchase emissions allowances if the airline exceeds the number of free allowances allocated to it under the ETS. The scope of the ETS was narrowed so that it currently applies only to flights within the EEA through 2023 to align with the pilot phase of CORSIA. In 2023, the EU adopted new legislation extending this narrow scope of the EU ETS until 2027 but requires a review of CORSIA’s effectiveness in 2026, which could potentially lead to expansion of the EU ETS to include all flights departing the EU and EEA. As a result of the United Kingdom’s ("UK") withdrawal from the EU, UK flights are no longer part of the EU ETS and are instead regulated under a separate UK ETS scheme. UK ETS is applicable to UK domestic flights and flights from the UK to EEA countries.

Delta Air Lines, Inc. | 2023 Form 10-K 13

Item 1. Business

In 2017, ICAO also adopted aircraft certification standards to reduce carbon dioxide ("CO") emissions from new aircraft. The new aircraft certification standards applied to new fleet types in 2020 and will apply to in-production aircraft no later than 2028. These standards will not apply to existing in-service aircraft. In 2021, the EPA finalized GHG emission standards for new aircraft engines designed to implement the ICAO standards on the same timeframe contemplated by ICAO, and these standards have been upheld in response to legal challenges. Like the ICAO standards, the final EPA standards would not apply to engines on in-service aircraft.

The airline industry may face additional regulation of aircraft emissions in the U.S. and abroad and become subject to further taxes, charges or additional requirements to obtain permits or purchase allowances or emission credits for GHG emissions in various jurisdictions. For example, in 2023, the EU adopted legislation that will impose a SAF mandate on fuel supplied at EU airports. The mandate requires that, of the jet fuel supplied in the EU, 2% must be SAF beginning in 2025, and the percentage increases incrementally over time to 70% in 2050. This mandate is expected to increase the cost of SAF in the EU. Additional regulation could result in taxation, regulatory or permitting requirements from multiple jurisdictions for the same operations and significant costs for us and the airline industry. In addition to direct costs, such regulation could result in increased fuel costs passed through from fuel suppliers affected by any such regulations. Certain airports have also adopted, and others could in the future adopt, GHG emission or climate-related goals and requirements that could impact our operations or require us to make changes or investments in our infrastructure. We are monitoring and evaluating the potential impact of such developments.

Noise. The Airport Noise and Capacity Act of 1990 recognizes the rights of operators of airports with noise problems to implement local noise abatement programs so long as such programs do not interfere unreasonably with interstate or foreign commerce or the national air transportation system. This statute generally provides that local noise restrictions on Stage 3 aircraft first effective after October 1, 1990 require FAA approval. While we have had sufficient scheduling flexibility to accommodate local noise restrictions in the past, our operations could be adversely impacted if locally imposed regulations become more restrictive or widespread. In addition, foreign governments may enact or allow airports to enact similar restrictions, which could adversely impact our international operations or require significant expenditures in order for our aircraft to comply with the restrictions. For example, in 2022, to reduce noise, the Netherlands announced a multi-phase plan to reduce the maximum number of flights authorized annually at Amsterdam’s Schiphol Airport. In 2023, airlines and airline associations, including Delta and KLM, challenged the initial phase of the plan. The legal challenge resulted in a ruling against the industry, but an appeal is currently pending before the Supreme Court of the Netherlands. The U.S., the European Commission and other governments also raised legal concerns about the plan with the Dutch government. In November 2023, the Netherlands suspended the initial phase of the plan; however, the government continues to support a second-phase plan to reduce flights at Schiphol. The outcome cannot be determined at this time.

Refinery Matters. Monroe's operation of the Trainer refinery is subject to numerous environmental laws and extensive regulations, including those relating to the discharge of materials into the environment, waste management, pollution prevention measures and greenhouse gas and other air emissions.

Under the Energy Policy Act of 2005, as expanded by the Energy Independence and Security Act of 2007, the Renewable Fuel Standard ("RFS") was created, setting up specific targets of renewable fuel to be used in the U.S. economy by mandating the blending of renewable fuels into gasoline and on-road diesel ("Transportation Fuels"). Renewable Identification Numbers ("RINs") are assigned to renewable fuels produced by or imported into the U.S. that are blended into Transportation Fuels to demonstrate compliance with this obligation. A refinery may meet its obligation under RFS by blending the necessary volumes of renewable fuels with Transportation Fuels, by purchasing RINs in the open market or through a combination of blending and purchasing RINs. Because Monroe is able to blend only a small amount of renewable fuels, it must purchase the majority of its RINs requirement in the secondary market. Market prices for RINs have been volatile and marked by periods of sharp increases and decreases primarily in response to speculation about what the EPA and/or the U.S. Congress will do with respect to compliance obligations. In June 2023, the EPA finalized RFS volume requirements for 2023, 2024 and 2025. These volume requirements are below projected production of Transportation Fuels, which has resulted in a decrease in the price of RINs.

Civil Reserve Air Fleet Program

We participate in the Civil Reserve Air Fleet program (the "CRAF Program"), which permits the U.S. military to use the aircraft and crew resources of participating U.S. airlines during airlift emergencies, national emergencies or times of war. We have agreed to make available under the CRAF Program a portion of our international aircraft during the contract period that ends on September 30, 2024. The CRAF Program has only been activated three times since it was created in 1951, most recently in 2021 to support the military’s effort to evacuate people from Afghanistan following the withdrawal of U.S. troops from the country.

Delta Air Lines, Inc. | 2023 Form 10-K 14

Item 1. Business

Information About Our Executive Officers

Edward H. Bastian, Age 66: Chief Executive Officer of Delta since May 2016; President of Delta (September 2007 - May 2016); President of Delta and Chief Executive Officer Northwest Airlines, Inc. (October 2008 - December 2009); President and Chief Financial Officer of Delta (September 2007 - October 2008); Executive Vice President and Chief Financial Officer of Delta (July 2005 - September 2007); Chief Financial Officer of Acuity Brands (June 2005 - July 2005); Senior Vice President - Finance and Controller of Delta (2000 - April 2005); Vice President and Controller of Delta (1998 - 2000).

Glen W. Hauenstein, Age 63: President of Delta since May 2016; Executive Vice President - Chief Revenue Officer of Delta (August 2013 - May 2016); Executive Vice President - Network Planning and Revenue Management of Delta (April 2006 - July 2013); Executive Vice President and Chief of Network and Revenue Management of Delta (August 2005 - April 2006); Vice General Director - Chief Commercial Officer and Chief Operating Officer of Alitalia (2003 - 2005); Senior Vice President- Network of Continental Airlines (2003); Senior Vice President - Scheduling of Continental Airlines (2001 - 2003); Vice President Scheduling of Continental Airlines (1998 - 2001).

Allison C. Ausband, Age 61: Executive Vice President - Chief Customer Experience Officer of Delta since June 2021; Senior Vice President - In-Flight Service of Delta (September 2014 - May 2021); Vice President - Reservation Sales and Customer Care of Delta (January 2010 - September 2014).

Alain Bellemare, Age 62: President - International of Delta since January 2021; Chief Executive Officer of Bombardier (February 2015 - March 2020); President and Chief Executive Officer of United Technologies Corporation Propulsion & Aerospace Systems (June 2011 - February 2015).

Peter W. Carter, Age 60: Executive Vice President - External Affairs of Delta since October 2022; Executive Vice President - Chief Legal Officer of Delta (July 2015 - October 2022); Partner of Dorsey & Whitney LLP (1999 - 2015), including co-chair of Securities Litigation and Enforcement practice group, chair of Policy Committee and chair of trial department.

Daniel C. Janki, Age 55: Executive Vice President - Chief Financial Officer of Delta since July 2021; Senior Vice President of General Electric Company (GE) and Chief Executive Officer of GE Power Portfolio (October 2020 - June 2021); Senior Vice President, Business and Portfolio Transformation of GE (2018 - 2020); Senior Vice President, Treasurer and Global Business Operations of GE (2014 - 2017); Senior Vice President, CEO of GE Energy Management (2012 - 2013).

John E. Laughter, Age 53: President - Delta TechOps and Chief of Operations since October 2023; Executive Vice President - Chief of Operations of Delta (June 2021 - October 2023); Senior Vice President and Chief of Operations of Delta (October 2020 - June 2021); Senior Vice President - Flight Operations of Delta (March 2020 - October 2020); Senior Vice President - Corporate Safety, Security and Compliance of Delta (August 2013 - March 2020); Senior Vice President - Maintenance Operations of Delta (March 2008 - July 2013); Vice President - Maintenance of Delta (December 2005 - March 2008).

Rahul Samant, Age 57: Executive Vice President - Chief Information Officer of Delta since January 2018; Senior Vice President and Chief Information Officer of Delta (February 2016 - December 2017); Senior Vice President and Chief Digital Officer of American International Group, Inc. (January 2015 - February 2016); Senior Vice President and Global Head, Application Development and Management of American International Group, Inc. (September 2012 - December 2014); Managing Director of Bank of America (1999 - September 2012).

Steven M. Sear, Age 58: Executive Vice President - Global Sales of Delta since February 2016; Senior Vice President - Global Sales of Delta (December 2011 - February 2016); Vice President - Global Sales of Delta (October 2008 - December 2011); Vice President - Sales & Customer Care of Northwest Airlines, Inc. (June 2005 - October 2008).

Joanne D. Smith, Age 65: Executive Vice President and Chief People Officer of Delta since October 2014; Senior Vice President - In-Flight Service of Delta (March 2007 - September 2014); Vice President - Marketing of Delta (November 2005 - February 2007); President of Song (January 2005 - October 2005); Vice President - Marketing and Customer Service of Song (November 2002 - December 2004).

Mike Spanos, Age 59: Chief Operating Officer of Delta since June 2023; President and Chief Executive Officer of Six Flags Entertainment Corporation (November 2019 - November 2021); Chief Executive Officer, Asia, Middle East and North Africa of PepsiCo, Inc. (January 2018 - November 2019); previously served in a variety of management roles of increasing responsibility at PepsiCo, Inc. since 1993.

Delta Air Lines, Inc. | 2023 Form 10-K 15

Item 1. Business

Additional Information

Our company website is located at www.delta.com and our investor relations website is located at ir.delta.com. We make available free of charge on our investor relations websiteour Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K and amendments to those reports as soon as reasonably practicable after these reports are filed with or furnished to the Securities and Exchange Commission ("SEC"). Information on our website, including our investor relations website, is not incorporated into this Form 10-K or our other securities filings and is not a part of those filings.

Delta Air Lines, Inc. | 2023 Form 10-K 16

Item 1A. Risk Factors

ITEM 1A. RISK FACTORS

In addition to the other information set forth in this report, you should carefully consider the following material risk factors applicable to Delta. As described below, these risks could materially affect our business, financial condition or results of operations in the future.

Risk Factors Relating to Delta

We are at risk of losses and adverse publicity stemming from a serious accident involving our aircraft or aircraft of our airline partners.

An aircraft crash or other serious accident involving our aircraft or those of our airline partners could expose us to significant liability. Although we believe that our insurance coverage is appropriate, we may be forced to bear substantial losses from an accident in the event that the coverage was not sufficient.

In addition, any accident involving an aircraft that we operate or an aircraft that is operated by an airline that is one of our regional carriers or codeshare, alliance or joint venture partners could create a negative public perception about safety and reliability for aviation authorities and the public, which could harm our reputation, resulting in air travelers being reluctant to fly on our aircraft and therefore harm our business.

Breaches or lapses in the security of the technology systems we use and rely on could compromise the data stored within them and consequently expose us to liability, disruption to our operations and damage to our reputation, any or all of which could have a material adverse effect on our business.

As a regular part of our ordinary business operations, we collect and store sensitive data, including information necessary for our operations, personal information of our passengers and employees and information of our business partners. The secure operation of our networks and systems, and those of our business partners and third-party service providers, on which this type of information is stored, processed and maintained is critical to our business operations and strategy. These networks and systems are subject to an increasing threat of continually evolving cybersecurity risks, which we must manage.

We expect unauthorized parties to continue attempting to gain access to our systems or information, or those of our business partners and third-party service providers, including through fraud or other means of deception, or introduction of malicious code, such as malware and ransomware. If successful, these actions could cause harm to our computer systems or compromise data stored on our computer networks or those of our business partners and third-party service providers, potentially causing us to incur remedial, legal and other costs, which could be material. Hardware or software we or our business partners or third-party service providers develop, acquire or use in connection with our systems may contain defects that could unexpectedly compromise information security.

The methods used to obtain unauthorized access, disable or degrade service or sabotage systems are constantly evolving and may be difficult to anticipate or to detect for long periods of time. As a result of these types of risks and regular attacks on our systems, we regularly review and update procedures and processes to prevent and protect against unauthorized access to our systems and information and inadvertent misuse of data. In addition to continuously assessing risk and reviewing our procedures, processes and technologies, we continue to educate our employees about these risks and to monitor, review and update the process and control requirements we expect third parties and vendors to leverage and implement for the protection of information regarding our customers, employees or business partners that is in their care. However, the constantly changing nature of the threats means that we may not be able to prevent all information security breaches or misuse of data. In addition, as cybercriminals become more sophisticated, the cost of proactive defensive measures continues to increase.

We are also subject to evolving global privacy and security regulatory obligations and an increasing customer focus on privacy issues and data security in the United States and abroad, as well as to geopolitical risks associated with international data transfer. The compromise of our or our business partners’ or third-party service providers’ technology systems resulting in the loss, interruption, disclosure, misappropriation of, or access to, our information or that of our customers, employees or business partners could result in legal claims or proceedings, liability or regulatory penalties under laws protecting the privacy and security of personal information, disruption to our operations and damage to our reputation, any or all of which could adversely affect our business. The costs to remediate breaches and similar system compromises that do occur could be material.

Delta Air Lines, Inc. | 2023 Form 10-K 17

Item 1A. Risk Factors

Disruptions of our information technology infrastructure could interfere with our operations, possibly having a material adverse effect on our business.

Disruptions in our information technology capability could result from a technology error or failure impacting our internal systems, whether hosted internally at our data centers or externally at third-party locations, or large-scale external interruption in technology infrastructure support on which we depend, such as power, telecommunications or the internet. The operation of our technology systems and the use of related data may also be vulnerable to a variety of other sources of interruption, including natural disasters, terrorist attacks, computer viruses, hackers and other security issues. A significant individual, sustained or repeated failure of our information technology infrastructure, including third-party networks we utilize and on which we depend, could impact our operations and our customer service, result in increased costs and damage our reputation. While we have in place initiatives to prevent disruptions and disaster recovery plans and continue to invest in improvements to these initiatives and plans, we have previously experienced infrastructure disruptions. These measures may not be adequate to prevent a future business disruption and any material adverse financial and reputational consequences to our business as recent outages of large cloud providers whom we rely on has shown.

Failure of the technology we use to perform effectively could have a material adverse effect on our business.

We are dependent on technology initiatives and capabilities to provide customer service and operational effectiveness in order to compete in the current business environment. For example, substantially all of our tickets are issued to our customers as electronic tickets, and a growing number of our customers check in using our website, airport kiosks and our FlyDelta mobile application. We have made and continue to make significant investments in customer facing technology such as delta.com, the FlyDelta mobile application, in-flight wireless internet, check-in kiosks, customer service applications, application of biometric technology, airport information displays and related initiatives, including security for these initiatives. We are also investing in significant upgrades to technology infrastructure and other supporting systems and transitioning to cloud-based technologies. The performance, reliability and security of the technology we use are critical to our ability to serve customers. If this technology does not perform effectively, including as a result of the implementation or integration of new or upgraded technologies or systems, our business and operations would be negatively affected, which could be material.

Our business and results of operations are dependent on the price of aircraft fuel. High fuel costs or cost increases, including in the cost of crude oil, could have a material adverse effect on our results of operations.

Our results of operations are significantly impacted by changes in the price of aircraft fuel. Fuel costs represented 21%, 24% and 20% of our operating expense in 2023, 2022 and 2021, respectively. Fuel prices are highly volatile and at times have increased substantially. In 2023, our average fuel price per gallon was $2.82, ranging from a monthly low of approximately $2.41 per gallon to a monthly high of approximately $3.18 per gallon.

We acquire a significant amount of jet fuel from Monroe and through strategic agreements associated with the refinery that Monroe has with third parties. The cost of the fuel we purchase under these arrangements remains subject to volatility in the cost of crude oil and jet fuel. In addition, we have historically purchased a significant amount of aircraft fuel in addition to what we obtain from Monroe. Our aircraft fuel purchase contracts alone do not provide material protection against price increases as these contracts typically establish the price based on industry standard market price indices.

Because passengers often purchase tickets well in advance of their travel, a significant rapid increase in fuel price may result in the fare charged not covering that increase. At times in the past, we often were not able to increase our fares to offset fully the effect of increases in fuel costs, and we may not be able to do so in the future.

Significant extended disruptions in the supply of aircraft fuel, including from Monroe, could have a material adverse effect on our business and results of operations.

Weather-related events, natural disasters, political disruptions or disputes involving oil-producing countries, changes in governmental policy concerning aircraft fuel production, transportation or taxes, changes in refining capacity or refining priorities, environmental concerns and other unpredictable events may impact crude oil and fuel supply and could result in shortages in the future. Shortages in fuel supplies could have negative effects on our business and results of operations.

Delta Air Lines, Inc. | 2023 Form 10-K 18

Item 1A. Risk Factors

Unplanned disruptions or interruptions of production at the refinery could have a negative impact on our ability to acquire jet fuel needed for our operations. Disruptions or interruptions of production at the refinery could result from various sources including a major accident or mechanical failure, interruption of supply or delivery of crude oil, work stoppages relating to organized labor issues, or damage from severe weather or other natural or man-made disasters, including acts of terrorism. If the refinery were to experience an unexpected interruption in operations, disruptions in fuel supplies could have negative effects on our results of operations and financial condition. In addition, the financial benefits from the operation of the refinery could be materially adversely affected (to the extent not recoverable through insurance) because of lost production and repair costs.

If Monroe's cost of producing non-jet fuel products significantly exceeds the value it receives for those products, the financial benefits we expect to achieve through the ownership of the refinery and our consolidated results of operations could be materially adversely affected.

Our commercial relationships with airlines in other parts of the world and the investments that we have in certain of those carriers may not produce the results or returns we expect.

An important part of our strategy to expand our global network has been to develop and expand strategic relationships with a number of airlines through joint ventures and other forms of cooperation and support, including equity investments. These relationships and investments involve significant challenges and risks, including that joint ventures or cooperation agreements may be subject to ongoing review and renewal requirements and may not generate the expected financial results, or that we may not realize a satisfactory return on our investments. For example, the DOT's approval of and antitrust immunity grant for our joint cooperation agreement with Aeroméxico is subject to a pending renewal application with the DOT, which was tentatively dismissed pursuant to an Order to Show Cause issued by the DOT on January 26, 2024. The existing immunity remains in effect pending final adjudication of the renewal application, the timing and outcome of which cannot be predicted at this time.

We are dependent on these other carriers for significant aspects of our network in the regions in which they operate. While we work closely with these carriers, we do not have control over their operations or business methods. To the extent that the operations of any of these carriers are disrupted over an extended period or their actions have a significant adverse effect on our operations, our results of operations could be materially adversely affected. If our commercial arrangements with any of these partners are not maintained, any investments or other assets associated with those partners could become impaired, and our business and results of operations could be materially adversely affected.

A significant disruption in, or other problems with respect to, the operations or performance of third parties on which we rely, including third-party carriers, could have a material adverse effect on our business and results of operations.

We rely on the operations and performance of third parties in a number of areas that are important to our business, including third-party regional carriers, international alliance partners and ground operation providers at some airports. While we have agreements with certain of these third parties that define expected service performance, we do not have direct control over their operations. To the extent that the operations of a third-party on which we rely is significantly disrupted or if these third parties experience significant performance issues (including failing to satisfy any applicable performance standards) or fail to meet any applicable compliance requirements, our revenue may be reduced, our expenses may be increased and our reputation may be harmed, any or all of which could result in a material adverse effect on our business and results of operations.

Some regional carriers, including our wholly owned subsidiary, Endeavor, are facing a shortage of qualified pilots and experiencing operating constraints as a result. If this shortage becomes more widespread, third-party regional carriers may not be able to comply with their obligations to us, and Endeavor may not be able to perform as expected, which could reduce our expected capacity and affect our revenue, resulting in a material adverse effect on our business and results of operations.

Delta Air Lines, Inc. | 2023 Form 10-K 19

Item 1A. Risk Factors

Agreements governing our debt, including our credit facilities and our SkyMiles financing agreements, include financial and other covenants. Certain of these covenants impose restrictions on our business, and failure to comply with any of the covenants in these agreements could result in events of default.

Our debt agreements contain various affirmative, negative and financial covenants, including our credit facilities and our SkyMiles financing agreements, each of which contains a minimum liquidity covenant. Certain of our debt agreements and our SkyMiles financing agreements contain minimum coverage ratios. A decline in these coverage ratios, including due to factors that are beyond our control, could trigger an early amortization event or, if applicable, require us to post additional collateral. Our SkyMiles financing agreements also restrict our ability to, among other things, change the policies and procedures of the SkyMiles program in a manner that would reasonably be expected to materially impair repayment of our SkyMiles debt. Complying with certain of the covenants in our debt agreements, and other restrictive covenants that may be contained in any future debt agreements, could limit our ability to operate our business and to take advantage of business opportunities that are in our long-term interest.

While the covenants in our debt agreements are subject to important exceptions and qualifications, if we fail to comply with them and are unable to obtain a waiver or amendment, refinance the indebtedness subject to these covenants or take other mitigating actions, an event of default would result. These arrangements also contain other events of default customary for such financings. If an event of default were to occur, the lenders or noteholders could, among other things, declare outstanding amounts due and payable and where applicable and subject to the terms of relevant collateral agreements, repossess collateral, including aircraft or other valuable assets. In addition, an event of default or acceleration of indebtedness under one agreement could result in an event of default under other of our financing agreements. The acceleration of significant indebtedness could require us to seek to renegotiate, repay or refinance the obligations under our financing arrangements, and there is no assurance that such renegotiation or refinancing efforts would be successful.

Employee strikes and other labor-related disruptions may have a material adverse effect on ouroperations.

Our business is labor intensive, utilizing large numbers of pilots, flight attendants, aircraft maintenance technicians, ground support personnel and other personnel. As of December 31, 2023, 20% of our workforce, primarily pilots, was unionized. Relations between air carriers and labor unions in the United States are governed by the Railway Labor Act, which provides that a collective bargaining agreement between an airline and a labor union does not expire, but instead becomes amendable as of a stated date. The Railway Labor Act generally prohibits strikes or other types of self-help actions both before and after a collective bargaining agreement becomes amendable, unless and until the collective bargaining processes required by the Railway Labor Act have been exhausted. Separately, the NLRA governs Monroe’s relations with the union representing their employees, which generally allows self help after a collective bargaining agreement expires.

If we or our subsidiaries are unable to reach agreement with any of our unionized work groups in future negotiations regarding the terms of their collective bargaining agreements or if additional segments of our workforce become unionized, we may be subject to work interruptions or stoppages, subject to the requirements of the Railway Labor Act or the NLRA, as the case may be. Strikes or labor disputes with our unionized employees may have a material adverse effect on our ability to conduct business. Likewise, if third-party regional carriers with which we have contract carrier agreements are unable to reach agreement with their unionized work groups in current or future negotiations regarding the terms of their collective bargaining agreements, those carriers may be subject to work interruptions or stoppages, subject to the requirements of the Railway Labor Act, which could have a material adverse effect on our operations.

Our results can fluctuate due to seasonality and other factors.

Our results of operations are impacted by a number of factors including seasonality and changing economic and other conditions beyond our control. Demand for air travel is typically higher in the June and September quarters, particularly in our international markets, because there is more vacation travel during these periods than during the remainder of the year. The seasonal shifting of demand causes our financial results to vary on a quarterly basis. Changes in the value of our equity investments in other airlines and airline service companies can also be significant and cause fluctuations in our results. Other factors that may affect our results include severe weather conditions and natural disasters (or other environmental events), which could significantly disrupt service and create air traffic control problems. In addition, increases in the frequency, severity or duration of thunderstorms, hurricanes, typhoons, floods or other severe weather events, including from changes in the global climate and rising global temperatures, could result in increases in delays and cancellations, turbulence-related injuries and fuel consumption to avoid such weather, any of which could result in loss of revenue and higher costs. Because of fluctuations in our results from seasonality and other factors, results of operations for a historical period are not necessarily indicative of results of operations for a future period and results of operations for an interim period are not necessarily indicative of results of operations for an entire year.

Delta Air Lines, Inc. | 2023 Form 10-K 20

Item 1A. Risk Factors

An environmental or other incident associated with the operation of the Monroe refinery could have a material adverse effect on our consolidated financial results if insurance is unable to cover a significant liability. In addition, such an incident could damage our reputation.

Monroe's refining operations are subject to various hazards unique to refinery operations, including explosions, fires, toxic emissions and natural catastrophes. Monroe could incur substantial losses, including cleanup costs, fines and other sanctions and third-party claims, and its operations could be interrupted, as a result of such an incident. Monroe's insurance coverage does not cover all potential losses, costs or liabilities, and Monroe could suffer losses for uninsurable or uninsured risks or in amounts greater than its insurance coverage. In addition, Monroe's ability to obtain and maintain adequate insurance may be affected by conditions in the insurance market over which it has no control. If Monroe were to incur a significant liability for which it is not fully insured or for which insurance companies do not or are unable to provide coverage, this could have a material adverse effect on our consolidated financial results of operations or consolidated financial position. In addition, because of our ownership of Monroe, the occurrence of an environmental or other incident could result in damage to our reputation, which could have a material adverse effect on our financial results.

The operation of the refinery by Monroe is subject to significant environmental regulation. Failure to comply with environmental regulations or the enactment of additional regulation applicable to Monroe could have a material adverse effect on our consolidated financial results.

Monroe’s operations are subject to extensive environmental, health and safety laws and regulations, including those relating to the discharge of materials into the environment, waste management, pollution prevention measures and greenhouse gas emissions, which are subject to change over time. Monroe could incur fines and other sanctions, cleanup costs and third-party claims as a result of violations of or liabilities under environmental, health and safety requirements, which if significant, could have a material adverse effect on our consolidated financial results. In addition, the enactment of new, more stringent environmental laws and regulations, including any laws or regulations relating to greenhouse gas emissions, could significantly increase the level of expenditures required for Monroe or restrict its operations.

In particular, in administering the RFS, created by the U.S. Congress under the Energy Independence and Security Act of 2007, the EPA created a program to ensure compliance with RFS mandates for the blending of renewable fuels into Transportation Fuels. RINs are assigned to renewable fuels produced or imported into the U.S. that are blended into Transportation Fuels to demonstrate compliance with this obligation. A refinery may meet its obligation under RFS by blending the necessary volumes of renewable fuels with Transportation Fuels, by purchasing RINs in the open market, or by a combination of blending and purchasing RINs.

Because Monroe is able to blend only a small amount of renewable fuels, it must purchase the majority of its RINs obligation in the secondary market. As a result, Monroe is exposed to the market price of RINs. Market prices for RINs have been volatile, marked by periods of sharp increases and decreases primarily in response to speculation about what the EPA and/or the U.S. Congress will do with respect to compliance obligations. We cannot predict these actions or the future prices of RINs. Monroe’s purchase of RINs at elevated prices in the future could have a material impact on our consolidated results of operations and cash flows.

Existing laws or regulations could change, and the minimum volumes of renewable fuels that must be blended with refined petroleum products may increase. Increases in the volume of renewable fuels that must be blended into Monroe’s products could limit the refinery’s production if sufficient numbers of RINs are not available for purchase, or if relief from this requirement is not obtained, which could have a material adverse effect on our consolidated financial results.

Significant damage to our reputation and brand, including as a result of significant adverse publicity or inability to achieve certain sustainability goals, could materially adversely affect our business and financial results.

Maintaining our reputation and global brand is critical to our business. We operate in a highly visible and public environment with significant real-time exposure to traditional and social media. Adverse publicity, whether justified or not, can rapidly spread, including through social or digital media. In particular, passengers can use social media to portray interactions with Delta, without context, in a manner that can be quickly and broadly disseminated. To the extent we are unable to respond in a timely and appropriate manner to adverse publicity, our brand and reputation may be damaged.

Delta Air Lines, Inc. | 2023 Form 10-K 21

Item 1A. Risk Factors

Our reputation and brand could also be adversely impacted by, among other things, failure to make progress toward and achieve our environmental sustainability and diversity, equity and inclusion goals, as well as public pressure from investors or policy groups to change our policies or negative public perception of the environmental impact of air travel. For example, we have established ambitious goals to reduce our greenhouse gas emissions. Achieving these ambitious goals will require significant capital investment from manufacturers and other stakeholders, as we are unable to achieve these goals using our existing fleet, current technologies and available fuel sources. We are continuing to develop our climate strategy and transition plan; however, our ability to execute on such a plan is subject to substantial risks and uncertainties, as it is dependent on the actions of governments and third parties and will require, among other things, significant capital investment, including from third parties, research and development from manufacturers and other stakeholders, along with government policies and incentives to reduce the cost, and incent production, of SAF and other technologies that are not presently in existence or available at scale. Significant damage to our reputation and brand could have a material adverse effect on our business and financial results, including as a result of litigation related to any of these matters.

If we lose senior management and other key employees and they are not replaced by individuals with comparable skills, or we otherwise fail to maintain our company culture, our business and results of operations could be materially adversely affected.

We are dependent on the experience and industry knowledge of our officers and other key employees to design and execute our business plans. If we experience a substantial turnover in our leadership and other key employees and we are not able to replace these persons with individuals with comparable skills, or we otherwise fail to maintain our company culture, our performance could be materially adversely impacted.Furthermore, we may be unable to attract and retain additional qualified senior management and other key personnel as needed in the future.

Delta Air Lines, Inc. | 2023 Form 10-K 22

Item 1A. Risk Factors

Risk Factors Relating to the Airline Industry

Disease outbreaks, such as the COVID-19 pandemic or similar public health threats that may arise in the future, and measures implemented to combat them have had, and may in the future have, a material adverse effect on our business.

The COVID-19 pandemic, the measures governments and private parties implemented in order to stem its spread, and the general concern about the virus among travelers had a material adverse effect on the demand for worldwide air travel compared to historical levels, and consequently upon our business for an extended period. Similar disease outbreaks or public health threats that may arise in the future could have similarly adverse effects on our business.

Our operations were, and could in the future be, negatively affected further if our employees are quarantined or sickened as a result of exposure to a disease outbreak, or as a result of a similar public health crisis, or if they are subject to additional governmental curfews or "shelter in place" health orders or similar restrictions. Measures restricting the ability of our airport or in-flight employees to come to work negatively impact our service or operations, all of which could negatively affect our business.

We are unable to predict the extent to which disease outbreaks or other public health threats that may arise in the future may change our customers' behavior or travel patterns, which could have a material impact on our business. The degree to which any future disease outbreaks or public health threats may impact our revenues, results of operations and financial condition is uncertain and will depend on future developments.

Terrorist attacks, geopolitical conflict or security events may adversely affect our business, financial condition and results of operations.

Terrorist attacks, geopolitical conflict or security events, or the fear or threat of any of these events, could have a significant adverse effect on our business. Despite significant security measures at airports and airlines, the airline industry remains a high profile target for terrorist groups. We rely on government provided threat intelligence and utilize private sources to constantly monitor for threats from terrorist groups and individuals, including from violent extremists both internationally and domestically, with respect to direct threats against our operations and in ways not directly related to the airline industry. In addition, the impact on our operations of avoiding areas of the world, including airspace, in which there are geopolitical conflicts and the targeting of commercial aircraft by parties to those conflicts can be significant. Security events, primarily from external sources but also from potential insider threats, also pose a significant risk to our passenger and cargo operations. These events could include random acts of violence and could occur in public areas that we cannot control.

Terrorist attacks, geopolitical conflict or security events, or the fear or threat of any of these events, even if not made directly on or involving the airline industry, could have a significant negative impact on us by discouraging passengers from flying, leading to decreased ticket sales and increased refunds. In addition, potential costs from these types of events include increased security costs, impacts from avoiding flight paths over areas in which conflict is occurring or could occur, such as flight redirections or cancellations, reputational harm and other costs. If any or all of these types of events occur, they could have a material adverse effect on our business, financial condition and results of operations.

The global airline industry is highly competitive and, if we cannot successfully compete in the marketplace, our business, financial condition and results of operations will be materially adversely affected.

The airline industry is highly competitive, marked by significant competition with respect to routes, fares, schedules (both timing and frequency), operational reliability, services, products, customer service and loyalty programs. Consolidation in the airline industry, changes in international alliances, the creation of immunized joint ventures and the rise of subsidized government-sponsored international carriers have altered and will continue to alter the competitive landscape in the industry, resulting in the formation of airlines and alliances with increased financial resources, more extensive global networks and competitive cost structures.

Delta Air Lines, Inc. | 2023 Form 10-K 23

Item 1A. Risk Factors

Our domestic operations are subject to significant competition from traditional network carriers, including American Airlines and United Airlines, national point-to-point carriers, including Alaska Airlines, JetBlue Airways and Southwest Airlines, and other discount or ultra-low-cost carriers, including Allegiant Air, Avelo Airlines, Breeze Airways, Frontier Airlines and Spirit Airlines. Some of these carriers have business models primarily focused on maintaining low costs, with the intention of providing service at lower fares to destinations served by Delta. In particular, we face significant competition at our domestic hubs and key airports either directly at those airports or at the hubs of other airlines that are located in close proximity. We also face competition in small- to medium-sized markets from regional jet operations of other carriers. Our ability to compete in the domestic market effectively depends, in part, on our ability to maintain a competitive cost structure. If we cannot maintain our costs at a competitive level, then our business, financial condition and results of operations could be materially adversely affected.

Our international operations are subject to competition from both foreign and domestic carriers, including from point-to-point carriers on certain international routes. Through alliance and other marketing and codesharing agreements with foreign carriers, U.S. carriers have increased their ability to sell international transportation, such as services to and beyond traditional European, Asian and Latin American gateway cities. Similarly, foreign carriers have obtained increased access to interior U.S. passenger traffic beyond traditional U.S. gateway cities through these relationships.

In particular, several joint ventures among U.S. and foreign carriers, including several of our joint ventures as well as those of our competitors, have received grants of antitrust immunity allowing the participating carriers to coordinate networks, schedules, pricing, sales and inventory. In addition, alliances formed by domestic and foreign carriers, including SkyTeam, the Star Alliance (among United Airlines, Lufthansa German Airlines, Air Canada and others) and the oneworld alliance (among American Airlines, British Airways, Qantas and others) have enhanced competition in international markets.

The airline industry also faces competition from surface transportation and technological alternatives such as virtual meetings, teleconferencing or videoconferencing. Increased competition from these sectors in both the domestic and international markets may have a material adverse effect on our business, financial condition and results of operations.

Extended interruptions or disruptions in service at major airports in which we operate or significant problems associated with a type of aircraft or engine we operate could have a material adverse effect on our financial condition and results of operations.

The airline industry is heavily dependent on business models that concentrate operations in major airports in the United States and throughout the world. An interruption or disruption at an airport or facility where we have significant operations, whether resulting from air traffic control delays, failure of computer systems or technology infrastructure, weather events or natural disasters, or performance issues from third-party service providers, if sustained for an extended period of time, could have a material adverse effect on our business, financial condition and results of operations.

Similarly, the airline industry is heavily dependent on a limited number of aircraft and engine manufacturers whose products are subject to extensive regulatory requirements. Any significant problems associated with an aircraft or engine type that we operate, including new aircraft or engine types, such as design defects, mechanical problems, contractual performance by the manufacturers or adverse perception by the public leading to customer avoidance, or adverse actions by the FAA resulting in limitations on use or grounding could have a negative impact on our operations if we are not able to substitute or replace the affected aircraft or engine type. Any of the foregoing could have a material adverse effect on our financial condition and results of operations.

The airline industry is subject to extensive government regulation, which is costly and could materially adversely affect our business.

Airlines are subject to extensive regulatory and legal compliance requirements that result in significant costs and may have material adverse effects on our business. For instance, the FAA from time to time issues directives and other regulations relating to the maintenance and operation of aircraft that necessitate significant expenditures and could carry operational implications. We expect to continue incurring significant expenses to comply with the FAA’s regulations. In addition, a directive or other regulation that has a significant operational impact on us could have a material adverse impact on our financial results.

Other laws, regulations, taxes and airport rates and charges have also been imposed from time to time that significantly increase the cost of airline operations, reduce revenues or otherwise impact our business. The industry is heavily taxed. Additional taxes and fees, if implemented, could negatively impact our results of operations.

Delta Air Lines, Inc. | 2023 Form 10-K 24

Item 1A. Risk Factors

Airport slot access is subject to government regulation and changes in slot regulations or allocations could impose a significant cost on the airlines operating in airports subject to such regulations or allocations or otherwise adversely affect an airline’s business. Certain of our hubs are among the most congested airports in the United States and have been, and could in the future be, the subject of regulatory action that might limit the number of flights and/or increase costs of operations at certain times or throughout the day. Air traffic control inefficiencies can also enhance these pressures.

In addition, inefficiencies in the U.S. air traffic control system, which is regulated by the FAA, can result in delays and disruptions of air traffic, especially during peak travel periods in certain congested markets. Failure to implement measures to improve the air traffic control system could lead to increased delays and inefficiencies in flight operations as demand for U.S. air travel increases, having a material adverse effect on our operations. Failure to update the air traffic control system in a timely manner, and the substantial funding requirements of an updated system that may be imposed on air carriers, may have an adverse impact on our financial condition and results of operations.

As an international carrier, we are subject to a wide variety of U.S. and foreign laws that affect trade, including tariff and trade policies, export and import requirements, taxes, monetary policies and other restrictions and charges. In particular, the imposition of significant tariffs with respect to aircraft that we are not able to mitigate could substantially increase our costs, which in turn could have a material adverse effect on our financial results.

In addition, some of our operations are in high-risk legal compliance environments. Failure to comply with trade sanctions and restrictions, the Foreign Corrupt Practices Act (the "FCPA") and similar anti-bribery laws in non-U.S. jurisdictions, as well as other applicable laws or regulations could result in litigation, assessment of damages, imposition of penalties or other consequences, any or all of which could harm our reputation and have an adverse effect on our financial results. In certain circumstances, we also may be subject to consequences of the failure of our airline partners to comply with laws and regulations, including U.S. laws to which they may be subject such as the FCPA.

We and other U.S. carriers are subject to U.S. and foreign laws regarding privacy and security of passenger and employee data that are not consistent in all countries in which we operate and which are continuously evolving, requiring ongoing monitoring and updates to our privacy and information security programs. Although we dedicate significant resources to manage compliance with global privacy and information security obligations, this challenging regulatory environment may pose material risks to our business, including increased operational burdens and costs, regulatory enforcement, and legal claims or proceedings.

The airline industry is subject to many forms of environmental regulation, including but not limited to regulation of hazardous substances, increased regulation to reduce emissions and other risks associated with climate change. The cost of compliance with more stringent environmental regulations, failure to comply with existing or future regulations or failure to otherwise manage the risks of climate change effectively could have a material adverse effect on our business.

Many aspects of our operations are subject to evolving and increasingly stringent federal, state, local and international laws governing environmental protection. Compliance with existing and future environmental laws and regulations could require capital investment and increase operational costs, and violations can lead to significant fines and penalties and reputational harm.

For example, in 2022, the EPA proposed regulations to define certain PFAS as "hazardous substances" under CERCLA, and the EPA has proposed to regulate certain PFAS as "hazardous constituents" under RCRA. The EPA is also proposing to regulate PFAS under the Safe Drinking Water Act. PFAS are used in a wide variety of consumer and industrial products, including the firefighting foams used to extinguish fuel-based fires at airports and refineries. Numerous states have adopted regulations governing PFAS as well, and some have adopted legislation prohibiting the manufacture, sale, distribution and/or use of firefighting foam containing intentionally added PFAS. EPA’s proposed rule under CERCLA, once finalized, could subject airports, airlines, and refineries, among others, to potential liability for cleanup of historical PFAS contamination associated with use of PFAS-containing firefighting foam, and some state laws require transition to alternative fire suppression systems. The ultimate impact and associated cost to Delta of these legislative and regulatory developments related to PFAS, including firefighting foam, cannot be predicted at this time.

Delta Air Lines, Inc. | 2023 Form 10-K 25

DAL - Delta Air Lines, Inc.

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