Community Health Options, a not-for-profit co-op insurance company based in Maine that also sells health plans in New Hampshire, will limit individual enrollments later this month because of “higher-than-expected claims costs.”

It’s an inauspicious sign for the company, which was one of the few successful co-ops created by the Affordable Care Act. Twelve of the ACA’s 23 co-ops have folded or are in the process of closing down, all of which occurred this year.