A federal whistleblower suit unsealed in late February alleges that Humana knew about billing fraud involving Medicare Advantage patients and didn't stop it. Ty Wright/Bloomberg via Getty Images hide caption

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In a previously unreleased letter, Office of Management and Budget Director Shaun Donovan told the Dept. of Health and Human Services to devise an action plan for reducing wasteful Medicare and Medicaid payments. Gary Cameron/Reuters/Landov hide caption

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A Texas lawsuit filed against 30 insurance plans in 15 states alleges that the companies overcharged Medicare for doctors' house calls. Laughing Stock/Corbis hide caption

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Sen. Chuck Grassley has questions about what the feds are doing to investigate allegations of Medicare Advantage fraud. Drew Angerer/Getty Images hide caption

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Carol Berman, of West Palm Beach, Fla., makes the case for policymakers to protect Medicare Advantage benefits during the Coalition for Medicare Choices' Medicare Advantage Food Truck stop in Washington, D.C., on Monday. Bill Clark/CQ-Roll Call/Getty Images hide caption

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Medicare beneficiaries who want to switch drug plans will have to make a decision earlier than usual this year.

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