Christina Pearson, a spokesman for the Department of Health and Human services, estimated that 500,000 people could receive notices as part of the “enrollment reconciliation process.”
The letters, being sent by private insurance companies on a government letterhead, say: “The purpose of this notice is to confirm your choice of a Medicare prescription drug plan and to ensure that you are enrolled in the plan you want.”

People have the option of staying in their original plan, but must indicate that desire by calling that insurer. Otherwise, the letter says, “you will no longer be able to use your membership card.”

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