(1) OWCP pays for inpatient medical services according to predetermined rates derived from the Medicare Inpatient Prospective Payment System (IPPS) used by the Centers for Medicare & Medicaid Services (CMS) for the Medicare program (42 CFR part 412).

(2) Inpatient hospital discharges are classified into diagnosis-related groups (DRGs). Each DRG groups together clinically similar conditions that require comparable amounts of inpatient resources. For each DRG, an appropriate weighting factor is assigned that reflects the estimated relative cost of hospital resources used with respect to discharges classified within that group compared to discharges classified within other groups.

(3) For each hospital discharge classified within a DRG, a payment amount for that discharge is determined by using the national weighting factor determined for that DRG, national standardized adjustments, and other factors which may vary by hospital, such as an adjustment for area wage levels. OWCP may also use other price adjustment factors as appropriate based on its processing experience and internal data.