Medicare-Eligible Beneficiaries

You must have Medicare Part B if:

  • You're eligible for Medicare, and
  • You turned 65 on or after April 1, 2001

If you don’t enroll in Medicare Part B, you can only get your prescriptions filled at military pharmacies.

Medicare Part D

Medicare's prescription drug plan, Medicare Part D, is available to anyone who's eligible for Medicare Part A or Part B.

TRICARE For Life includes prescription drug coverage through the TRICARE Pharmacy Program. This means you don't need Medicare Part D to have prescription coverage.

In some cases, you may benefit from buying a Medicare Part D plan. Here are some things to consider before you enroll in Medicare Part D:

TRICARE is Creditable Coverage

TRICARE is . This means you won’t pay extra if you decide to enroll in a Medicare prescription drug plan after your Initial Enrollment Period.

When you become eligible for Medicare Part D:

  • You'll receive a letter in the mail. 
  • It will explain how your TRICARE prescription drug plan works with Medicare Part D.  
  • Keep this letter for your records.  
  • You may need it to show that you don’t have to pay extra if you decide to enroll in Medicare Part D. 

If you do decide to enroll in a Medicare prescription drug plan:

  • TRICARE will pay second after Medicare.
  • You can enroll during your Medicare Initial Enrollment Period or the Medicare Open Enrollment Period each year.
  • The Open Enrollment Period is Oct. 15–Dec. 7, with prescription drug coverage beginning the next Jan. 1.

For More Information

Note: Beneficiaries who live overseas (non-U.S. territories) or who are in prison aren’t eligible for Medicare Part D.

Last Updated 7/2/2026