Medicare standard is primary to Tricare in all cases. Medicare Part D, if you elect it is also primary to Tricare. If you have a Medicare Advantage plan, let both Tricare and your MA know about the other, and they will organize the coordination of benefits.
One important thing to remember is that, if you have Medicare Part A and Tricare, in most cases you will also have to be enrolled in Medicare Part B to keep the Tricare coverage.
One important thing to remember is that, if you have Medicare Part A and Tricare, in most cases you will also have to be enrolled in Medicare Part B to keep the Tricare coverage.