Short answer: With coverage from a current employer, the employer plan pays first, Medicare second and TRICARE last. The retiree still needs Medicare Part A and Part B to use TRICARE For Life.
TRICARE’s own payment-order table for TRICARE For Life:
- Employer-sponsored coverage from current employment: the employer plan pays first, Medicare second, TRICARE last.
- Other insurance not based on current employment (retiree coverage, for example): Medicare first, the other insurance second, TRICARE last.
TRICARE generally pays after all other health insurance except Medicaid, TRICARE supplements and certain other federal programs. If the other plan denies a claim because its rules were not followed (out of network, no prior authorization), TRICARE may deny it too.
For employees under 65 who are not on Medicare, TRICARE also pays after the employer plan. Employers with 20 or more employees must offer TRICARE-eligible employees the same plan as everyone else (see the related card).