The A.M. Best analysis also revealed how the debt burden carried by all of the co-ops, which have cumulatively received nearly $2 billion in federal loans to start their businesses, has increased relative to their cash and other assets on hand.
And uncertainty over the future funding of a financial shock absorber for insurers built into Obamacare has left a number of the co-ops exposed to the possibility of having to write off what could be a large chunk of income that they are currently booking as an asset if that funding doesn't materialize, A.M. Best found.
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"A.M. Best is concerned about the financial viability of several of these plans," the rating agency said in its report on the co-ops, which the Affordable Care Act created with the goal of providing competitively priced insurance plans on Obamacare exchanges.
If some of those plans go out of business, it would mean fewer choices for consumers in their respective markets, and potentially higher premium prices.
The report comes weeks after the Iowa insurance commissioner put one of the co-ops, CoOportunity Health, into rehabilitation in late December, taking control of the insurer because of worries the co-op was not adequately capitalized. Nebraska's insurance department suspended CoOportunity Health's certificate of authority a day later.
Last Friday, Iowa's insurance commissioner said he would seek to liquidate the co-op. The more than 100,000 customers of the insurer in both his state and Nebraska have been urged to seek new coverage.
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On Jan. 15, Tennessee's Obamacare co-op, Community Health Alliance, announced it was freezing enrollment for the 2015 plan year as a "preventative measure to support the long-term viability of" the co-op, which hopes to resume general enrollment later this year for plans that go into effect in 2016.
That move came after the Tennessee co-op reported that enrollment in 2015 plans had grown "exponentially" from 2014.
Andrew Edelsberg, one of the authors of the A.M. Best report, said, "It's really hard to handicap it," when asked if he thought it was likely that one or more co-ops beyond Iowa's would fail.
But Edelsberg noted that when the agency looked at the co-ops last year, just seven had outstanding long-term low-interest loans from the federal government that amounted to more than 100 percent of the value of their capital and surplus.
"Now, they're all over 100 percent," he said.
Arizona's co-op Meritus Mutual Health Partners has long-term loans that are nearly 1,000 percent of the value of its capital and surplus—and 14 others have loans that total more than 200 percent of their assets, according to A.M. Best.