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How do I join a Medicare Part D prescription drug plan?

En español | There is no single Part D prescription drug plan in Medicare.  Coverage is provided through many plans that are run by private insurance companies and regulated by Medicare, and each offers a different array of coverage benefits and costs. So your first step is to select the plan that best meets your own needs and preferences. 

The best way of choosing a plan is according to the specific prescription drugs that you take. That’s because no plan covers all drugs, and the plans charge widely differing copays, even for the same drug. You can make this comparison in any of three ways:

  • Use Medicare’s online plan-finder program at If you enter your zip code, the names of the drugs you take, plus their dosage and how often you take them, the program identifies the plan(s) that cover your drugs at the least out-of-pocket cost.
  • Call the Medicare help line at 800-633-4227 (TTY 877-486-2048) and ask a customer service representative to perform the same search for you.
  • Contact your state health insurance assistance program (SHIP), which provides personal help from trained counselors on all Medicare issues — free from sales pressure and free of charge. To find the main toll-free phone number for your SHIP, goto and select your state.  

When you’ve found a plan that suits you, you can enroll in it online on the Medicare site described above or on the plan’s own website. Or you can enroll by phone, by calling the Medicare help line or calling the plan directly. You can find contact information for Part D plans in your area on the plan-finder program on Medicare’s website or by calling the Medicare help line. 

You can use the above methods for choosing a Part D plan regardless of whether it is a stand-alone plan or a Medicare Advantage plan (such as an HMO or PPO) that provides Part D drug coverage. If you consider Medicare Advantage plans, you need to compare their medical benefits as well as the drugs they cover and what they charge for them. 

For more details on how the Part D drug program works, see AARP’s consumer guide to the program at

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