(Bloomberg) — The Obama administration is investigating whether Aetna Inc. (NYSE:AET) misled elderly and disabled people about which pharmacies would fill prescriptions in Medicare drug plans the health insurer sold them.

Those customers will be able to quit their coverage and choose a new plan this year as a result, the federal government said. The Hartford, Conn.-based insurer provided incorrect information about its pharmacy network on Medicare’s website, on its own site and by telephone during the program’s 2015 enrollment period, which ended Dec. 7, Raymond Thorn, a spokesman for the Centers for Medicare & Medicaid Services (CMS), said in an e-mail.

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“The majority of pharmacies were not affected by this situation,” Cynthia Michener, an Aetna spokeswoman, said in an e-mail. The company will let its Medicare customers use any pharmacy that its plans covered last year until Feb. 28 while it sorts out the problem, she said.

Aetna could be fined or prohibited from enrolling new Medicare customers if the agency determines it intentionally misled Medicare patients, Thorn said. “We are considering appropriate compliance actions,” he said.

There were about 2.2 million people enrolled in Aetna’s Medicare drug plans in 2013, according to data compiled by Bloomberg.

The problem was brought to light by the National Community Pharmacists Association in Alexandria, Va., which represents independent pharmacies. Shortly after the beginning of the year, the group began receiving reports from its members that they were unexpectedly dropped from some of Aetna’s pharmacy networks.

See also: Investigators Find Suspicious Medicare Billing at 2,600 Pharmacies.

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