How Stable Are ACA Marketplaces?

The news that UnitedHealth Group is considering leaving the new health insurance marketplaces established under the Affordable Care Act (ACA) has prompted some concern about the their long-term viability. But United Health Group’s possible departure is not really the issue. The insurer was a minor player in the individual market before the ACA passed, and currently covers only about 5 percent of marketplace enrollees.

Rather, together with a few other developments, such as the failure of COOPs, the UnitedHealth Group announcement raised the fundamental question of whether the ACA marketplaces are enrolling sufficient numbers of people to ensure a well-balanced risk pool of healthy people and those with health problems. A pool where a majority of people have health problems could lead to higher premiums over time and destabilize marketplaces.