Only non-OPPS (Outpatient Prospective Payment System) providers are reimbursed under this methodology. Hospital-based surgery procedures are reimbursed under OPPS. Ambulatory surgery facility payments fall into one of 11 TRICARE grouper rates. All procedures identified by DHA for reimbursement under this methodology can be found at manuals.health.mil. TRICARE payment rates established under this system apply only to the facility charges for ambulatory surgery.