Per
32 CFR 199.6(b), institutional providers must
participate on all claims. In most cases (except for providers under
Diagnosis Related Groups (DRGs), Outpatient Prospective Payment
System (OPPS), and the inpatient mental health per diem payment
system), a participation agreement is required. By definition, participating
providers whether institutional providers, individual providers,
or other non-institutional providers, agree to accept the TRICARE
payment as full payment for the care services or supplies. Individual
providers and other non-institutional providers that are not participating
providers are limited to the amount they can collect from the beneficiary.