Aetna, one of the nation’s largest health insurers, announced Monday it is pulling out of all but four state exchanges in 2017. It is currently offering exchange plans in 15 states.

Aetna is only the latest insurer to reduce its marketplace presence, citing losses. The news also comes amid reports of double-digit premium hikes next year, another sign of financial trouble for insurers. Most of the nonprofit co-op plans created under the health care law have also shuttered.

“Following a thorough business review and in light of a second-quarter pretax loss of $200 million and total pretax losses of more than $430 million since January 2014 in our individual products, we have decided to reduce our individual public exchange presence in 2017, which will limit our financial exposure moving forward,” said Aetna chairman and CEO Mark Bertolini in a statement.

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