As open enrollment approaches, Marketplace health plans are navigating one of the most unpredictable seasons yet.

With ACA subsidies set to expire, more than 4 million Americans could lose coverage, leaving behind a smaller, higher-cost risk pool. The result? Premiums could rise by as much as 18%, out-of-pocket costs may increase, and more payers could exit the market, reducing member choice and further destabilizing the landscape.