UnitedHealth Group Inc., thelargest U.S. health insurer, has decided to call it quits in twostate Obamacare markets, in the latest challenge to PresidentBarack Obama’s health-care overhaul.

The insurer won’t sell plans for next year in Georgia andArkansas, according to state insurance regulators. Tyler Mason, aUnitedHealth spokesman, confirmed the exits and declined to saywhether the company would drop out of additional states.

Many insurers have found it difficult to turn a profit in thenew markets created by the Affordable Care Act, whereindividuals turned out to be more costly to care for than thecompanies expected. UnitedHealth and Aetna Inc. both posted lossesfrom the policies last year, as did big Blue Cross and Blue Shieldplans in states like North Carolina.

UnitedHealth began warning in November that it might exitObamacare markets as it racked up losses. In December, the companysaid it should have stayed out of the individualexchanges for longer.

UnitedHealth’s decision to stop offering ACA plans next yearmeans that people who are currently enrolled with the insurer willhave to choose a new health insurance provider next year. Itdoesn’t affect their current coverage.

While UnitedHealth is the biggestcarrier in the U.S., with about 42 million medical customers, ithas a smaller role in the ACA’s markets. The company had about650,000 in individual exchange-compliant policies as of Dec.31.

About 12.7 million people signed up for Obamacare coverage forthis year, including about 587,800 in Georgia and 73,600 inArkansas, according to the Centers for Medicare and MedicaidServices. CMS doesn’t disclose what insurers people picked.

Kenneth Ryan James, a spokesman for the Arkansas InsuranceDepartment, said UnitedHealth had a “small footprint” in the state,where Blue Cross and Blue Shield plans are dominant. UnitedHealthis also exiting that state’s small business exchange and a relatedbusiness selling private Medicaid plans, he said. The ArkansasDemocrat-Gazette earlier reported UnitedHealth’s decision to exitArkansas.

Including UnitedHealth, Georgia has nine health insurers thatcurrently offer ACA polices, according to Glenn Allen, a spokesmanfor the state’s insurance commissioner. Others include Aetna,Humana Inc. and Cigna Corp. No other company has yet told Georgiathat it’s exiting, and companies have until May 11 to decide, hesaid.

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