Beneficiaries Using TRICARE Retired Reserve
If entitled to Medicare Part A, you're not required to have Medicare Part B to purchase TRICARE Retired Reserve.
Even though you're not required to have Medicare Part B, we strongly encourage you to sign up for Part B when you are first eligible. If you don't you may be required to pay the Medicare Part B premium surchargeAn additional 10% for each 12-month period that you were eligible to enroll in Part B, but didn’t.
Learn more about TRICARE Retired Reserve