Short answer: Not if the employer has 20 or more employees. Federal law bars financial or other incentives for TRICARE-eligible employees not to enroll, and they must be offered the plan on the same terms as everyone else.
10 U.S.C. 1097c applies the Medicare Secondary Payer incentive ban to TRICARE: an employer may not offer financial or other incentives for a TRICARE-eligible employee not to enroll, or to drop enrollment, in a plan that would be primary to TRICARE. TRICARE-eligible employees must have the chance to join the group health plan and receive primary coverage in the same manner as similarly situated employees who are not TRICARE-eligible.
The section does not apply to employers with fewer than 20 employees. A ‘TRICARE-eligible employee’ here means someone covered under 10 U.S.C. 1086, generally a military retiree, a retiree’s family member or certain survivors. Enrolling in the employer plan does not affect the employee’s or spouse’s TRICARE eligibility.
A general cash-in-lieu-of-coverage offer made to everyone is a different question from one aimed at TRICARE-eligible employees; review any opt-out program with counsel if the workforce includes military retirees.