Cummins makes the engines and engine parts that keep trucks, buses, construction equipment, and power generators running around the world. It earns money two ways: selling engines and components when a customer places an order, and then selling replacement parts and repair services every time those products need maintenance. The five business segments are Engine (diesel and natural gas engines for trucks and industrial machines), Components (turbochargers, emission systems, axles, and brakes), Distribution (a global network of 640 distributor locations and more than 13,000 certified dealer locations that sell and service everything), Power Systems (large generators and industrial engines for data centers, mining, oil and gas, and defense), and Accelera (electric motors, batteries, and fuel cell technology still in early commercialization). PACCAR, which makes Kenworth and Peterbilt trucks, is the single largest customer, accounting for 13 percent of net sales in 2025. The diagram below traces where the money goes.

Five years of numbers tell a story of a business that grew fast, absorbed a painful legal blow, and is now navigating a slowdown in its biggest market while one newer segment surges. Revenue climbed from $24.0 billion in 2021 to $34.1 billion in 2023, then held almost flat through 2024 and dipped slightly to $33.7 billion in 2025. That plateau masks very different forces pulling in opposite directions.

Gross margin has crept upward every single year, from 23.7 percent in 2021 to 25.3 percent in 2025. That is a quiet but consistent improvement. The bigger swings show up in cash flow. Operating cash dropped sharply in 2022 and again in 2024, the year Cummins paid $1.9 billion to settle emissions violations with federal and California regulators. In 2025, with that payment behind them, operating cash bounced back to $3.6 billion and free cash flow recovered to $2.4 billion. Net debt has stayed elevated compared to 2021, sitting at $4.3 billion at the end of 2025, but the debt-to-capital ratio fell from 38.4 percent to 36.0 percent during the year as earnings rebuilt equity.

Inside those top-line numbers, the business is rotating. Heavy-duty truck engine shipments fell 23 percent in 2025 compared to 2024. The Engine segment, which once contributed a third of total profit, saw its share drop to 26 percent of total EBITDA (earnings before interest, taxes, depreciation, and amortization). Meanwhile, Power Systems grew 16 percent in revenue and 44 percent in EBITDA in a single year, driven by surging demand for data center generators. Distribution also grew 9 percent in revenue and 31 percent in EBITDA. Those two segments now generate the majority of total profit.

Research, development, and engineering spending held steady at $1.4 billion each year from 2023 through 2025. That is a large, consistent commitment. Some of it goes toward meeting tighter emissions standards for diesel engines. Some goes toward the electric and battery technologies inside Accelera. That split matters because the two bets require very different timelines to pay off.

Specific risks documented in the filings go well beyond the hydrogen setback. The emissions settlement is not fully behind the company. Cummins must comply with strict ongoing conditions from its agreement with the EPA, the California Air Resources Board, and the Department of Justice, covering roughly one million pickup truck engines. Failure to comply triggers additional financial penalties. Shareholder and consumer lawsuits related to the same emissions violations are still active.

The China exposure adds another layer of complexity. More than half of the income Cummins earns from joint ventures it does not fully control comes from three Chinese companies: Chongqing Cummins Engine, Dongfeng Cummins Engine, and Beijing Foton Cummins Engine. Combined, those three contributed $223 million to Cummins share of joint venture net income in 2025. Cummins does not control these entities, so a slowdown in Chinese industrial activity or tighter U.S. export controls on China could cut that income without Cummins having direct ways to respond. Tariffs between the U.S. and other countries add further uncertainty to both supply costs and the ability to collect payments from international customers.

Then there is the structural shift happening across all of Cummins' core markets. Customers are moving toward electric powertrains. Truck makers like Daimler, PACCAR, and Traton, who are also Cummins' biggest customers for diesel engines, are simultaneously among Cummins' listed competitors in the Accelera electric segment. If those OEMs bring electric drivetrains fully in-house, Cummins could lose both the diesel engine sale and the chance to supply the electric replacement.