LEWISTON — A Maine-based health insurance co-op with customers in Maine and New Hampshire says it is leaving the New Hampshire market for the 2017 plan year.

In December, Community Health Options stopped allowing an individual plan from the co-op through HealthCare.gov. The co-op decided to stop selling new plans because of significant enrollment growth over the past two years and higher-than-expected claims costs in 2015.

Existing individual policies will remain in effect through the end of their policy terms on Dec. 31. All existing individual policyholders will have the opportunity to select new coverage for 2017 during Open Enrollment which starts on Nov. 1 and runs through Jan. 31, 2017.

Health Options will retain its license in New Hampshire as well as its provider contracts.