By Emily Curran, Justin Giovannelli and Kevin Lucia

A reliable indicator of health insurance markets’ stability is insurer participation, including the number of insurers that elect to sell individual plans and whether they participate over subsequent years. In a recent analysis for the Commonwealth Fund, we looked at insurer participation in the state-based Affordable Care Act (ACA) marketplaces from 2014 to 2018, which sheds light on how state marketplaces have maintained competition despite uncertainty about the law’s future.

In the months leading up to the 2018 open enrollment period, there was widespread concern that the administration’s lack of commitment to implementing the ACA, including ending federal funding for cost-sharing subsidies, would lead many insurers to exit the marketplaces. Some insurers, including large publicly traded companies like Aetna and Humana, did announce in early spring 2017 that they would leave some states or markets. However, every county ultimately retained at least one insurer, and nearly half of marketplace enrollees can choose among three or more insurers in 2018. Overall, insurer participation in the state-based marketplaces was more stable than in the federally facilitated marketplace.

Insurers’ differing approaches offer insight into how they might react to continued regulatory changes—including the repeal of the individual mandate and loosening of requirements for short-term policies and association health plans—likely to affect markets in 2019.

To learn more about insurers’ diverging business strategies in the marketplaces, visit the Commonwealth Fund blog here.