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.