Centene, Oscar Health and UnitedHealthcare are making targeted expansions in Affordable Care Act markets for 2027, even as many rivals abandon the exchanges. Centene, the largest ACA insurer, is adding 55 counties across seven states, but it is also leaving Delaware and New Hampshire, so its overall footprint does not grow. UnitedHealthcare is exiting Georgia but adding counties in other states to keep its presence at roughly 1,300 counties. Oscar is adding 140 counties and entering South Carolina for the first time.
The moves come amid a difficult year for the exchanges. ACA enrollment fell by more than 4.6 million people after enhanced subsidies expired at the end of 2025, leaving a smaller and apparently sicker risk pool. Roughly a dozen carriers, including Cigna Healthcare, Molina and CareSource, plan to exit fully or partly. Remaining insurers are asking for a median 15% rate increase for 2027, the highest back-to-back increase since 2018.
Both expanding insurers are also trying new product designs. Centene is rolling out condition-specific plans for chronic conditions like diabetes and heart failure. Oscar is introducing a plan for early retirees transitioning to Medicare and expanding menopause-focused coverage. Open enrollment for 2027 begins Nov. 1 in most states.