Aetna has joined UnitedHealth Group and Humana in reconsidering — and even pulling back — its participation in Affordable Care Act (ACA) insurance marketplaces. Facing up to $300 million in ACA policy losses this year, Aetna announced it has canceled a planned expansion into five new state exchanges for 2017.

Also on the tablet are pullbacks in the 15 states Aetna currently services with ACA policies.

“We will look at the financial performance of the business over time, its trajectory and volatililty” market by market, announced Aetna CEO Mark T. Bertolini.

The insurer said it lost $200 million on ACA policies in the second quarter alone and expects the yearly loss to be $300 million or more.