Claims Reference · Inpatient Rehabilitation
IRF Claim Reference
How an IRF stay is billed to Medicare — the type of bill, the case-mix group (CMG) code on the claim, and the case-level adjustments that ride along. Background for institutional IRF billing.
No PHIReferenceInformational reference — paraphrased from CMS rules and manuals, not billing or legal advice; verify against the Medicare Claims Processing Manual (Pub. 100-04, Ch. 3) and your MAC.
The IRF claim at a glance
TOB 11x| Type of bill | 11x (inpatient hospital) — one admit-through-discharge claim per stay |
| Case-mix code | a 5-character CMG / HIPPS code on the Revenue Code 0024 line (FL 44) |
| Source of the CMG | derived from the IRF-PAI completed for the stay, via the IRF Grouper |
| Accommodation charges | room & board on accommodation revenue codes (010x–021x) |
| Payment | the Pricer returns the CMG payment on the RC 0024 line; total charges do not drive the non-outlier payment |
Revenue Code 0024 & the CMG code
FL 44The CMG is reported as a HIPPS-style code on the RC 0024 line. Covered charges on that line are zero — the Pricer prices the line from the CMG itself.
| First character | comorbidity-tier indicator (A = none; B, C, D = tiers) |
| Remaining characters | the CMG (rehabilitation impairment category and functional level) |
| Atypical CMGs | codes such as A5001 are assigned by Medicare for very short stays or in-hospital death — providers do not submit them |
Relative weights and average length of stay for each CMG/tier are published in CMS Table 2 and are not reproduced here — enter the weight in the estimator.
Adjustments that ride on the claim
Case-level| Transfer | a per-diem payment applies when the length of stay is below the CMG average and the patient-status code indicates a transfer |
| Interrupted / short stay / death | case-specific adjustments handled by the Pricer and Medicare systems |
| High-cost outlier | added when estimated cost (facility CCR × charges) exceeds the payment plus the outlier threshold |