[TRICARE is a] health care plan for active-duty service members, military retirees, and their families. Most people with TRICARE who are entitled to Part A must have Part B to keep TRICARE prescription drug benefits.
If you have TRICARE, you don’t need to join a Medicare Prescription Drug Plan. However, if you do, your Medicare [Part D] drug plan pays first and TRICARE pays second.
If you join a Medicare Advantage Plan (like an HMO or PPO) with prescription drug coverage, your Medicare Advantage Plan and TRICARE may coordinate their benefits if your Medicare Advantage Plan network pharmacy is also a TRICARE network pharmacy.
Otherwise, you can file your own claim to get paid back for your out-of-pocket expenses.
For more information, visit www.tricare.mil, or call the TRICARE Pharmacy Program at 1-877-363-1303. TTY users should call 1-877-540-6261.