FMS vs AAON Comparison

Fresenius Medical Care is the largest dialysis company in the world, treating nearly 300,000 patients from about 3,600 clinics worldwide as of December 2025. In addition to providing dialysis services, the firm is a leading supplier of dialysis products, including machines, dialyzers, and concentrates. Fresenius accounts for about 35% of the global dialysis products market, creating the world's only fully integrated dialysis business. Services account for about three-fourths of sales, while the balance is generated from medical technology products that enable dialysis treatments.

AAON Inc is a manufacturer of air-conditioning and heating equipment. The products include rooftop units, chillers, packaged outdoor mechanical rooms, air-handling units, makeup air units, energy-recovery units, condensing units, geothermal heat pumps, and self-contained units and coils. The company operates through three segments: AAON Oklahoma, AAON Coil Products, and BASX. It generates the majority of its revenue from the AAON Oklahoma segment which derives maximum revenue, engineers, manufactures, and sells, semi-custom, and custom HVAC systems, designs and manufactures control solutions, and sells retail parts to customers through retail part stores and online.