521
HIP REPLACEMENT WITH PRINCIPAL DIAGNOSIS OF HIP FRACTURE WITH MCC
MS-DRG 521 groups Medicare inpatient hospital stays for: HIP REPLACEMENT WITH PRINCIPAL DIAGNOSIS OF HIP FRACTURE WITH MCC. This is a surgical MS-DRG. It falls under MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue).
Payment & Classification Data
Official CMS values from the current fiscal year's IPPS Final Rule.
| Major Diagnostic Category | MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue |
| DRG Type | Surgical |
| Severity Level | MCC |
| Relative Weight | 2.8702 |
| Relative Weight (10% Cap Applied) | 2.8702 |
| Geometric Mean Length of Stay | 6 days |
| Arithmetic Mean Length of Stay | 7 days |
| Post-Acute Transfer DRG | Yes |
| Special Pay Transfer DRG | Yes |
Defining Codes (FY2026)
1,232 diagnosis codes can drive assignment here: M80.051A, M80.051G, M80.051K, M80.051P, M80.052A, M80.052G, M80.052K, M80.052P, M80.059A, M80.059G, M80.059K, M80.059P and 1,220 more.
96 procedure codes appear in its surgical logic (Hip Replacement with Principal Diagnosis of Hip Fracture: 96): 0SR9019, 0SR901A, 0SR901Z, 0SR9029, 0SR902A, 0SR902Z, 0SR9039, 0SR903A, 0SR903Z, 0SR9049, 0SR904A, 0SR904Z and 84 more.
From the CMS MS-DRG Definitions Manual (Appendices B and E). Assignment also depends on severity, discharge status and the rest of the claim.
Contextual Map
Every relationship of 521 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Major Diagnostic Category
- MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue [MDC]
Defining diagnoses (1232)
- M80.051A — Age-related osteoporosis with current pathological fracture, right femur, initial encounter for fracture [Grouper diagnosis]
- M80.051G — Age-related osteoporosis with current pathological fracture, right femur, subsequent encounter for fracture with delayed healing [Grouper diagnosis]
- M80.051K — Age-related osteoporosis with current pathological fracture, right femur, subsequent encounter for fracture with nonunion [Grouper diagnosis]
- M80.051P — Age-related osteoporosis with current pathological fracture, right femur, subsequent encounter for fracture with malunion [Grouper diagnosis]
- M80.052A — Age-related osteoporosis with current pathological fracture, left femur, initial encounter for fracture [Grouper diagnosis]
- M80.052G — Age-related osteoporosis with current pathological fracture, left femur, subsequent encounter for fracture with delayed healing [Grouper diagnosis]
- M80.052K — Age-related osteoporosis with current pathological fracture, left femur, subsequent encounter for fracture with nonunion [Grouper diagnosis]
- M80.052P — Age-related osteoporosis with current pathological fracture, left femur, subsequent encounter for fracture with malunion [Grouper diagnosis]
- and 1224 more
Defining procedures (96)
- 0SR9019 — Replacement of Right Hip Joint with Metal Synthetic Substitute, Cemented, Open Approach [Grouper procedure]
- 0SR901A — Replacement of Right Hip Joint with Metal Synthetic Substitute, Uncemented, Open Approach [Grouper procedure]
- 0SR901Z — Replacement of Right Hip Joint with Metal Synthetic Substitute, Open Approach [Grouper procedure]
- 0SR9029 — Replacement of Right Hip Joint with Metal on Polyethylene Synthetic Substitute, Cemented, Open Approach [Grouper procedure]
- 0SR902A — Replacement of Right Hip Joint with Metal on Polyethylene Synthetic Substitute, Uncemented, Open Approach [Grouper procedure]
- 0SR902Z — Replacement of Right Hip Joint with Metal on Polyethylene Synthetic Substitute, Open Approach [Grouper procedure]
- 0SR9039 — Replacement of Right Hip Joint with Ceramic Synthetic Substitute, Cemented, Open Approach [Grouper procedure]
- 0SR903A — Replacement of Right Hip Joint with Ceramic Synthetic Substitute, Uncemented, Open Approach [Grouper procedure]
- and 88 more
DRG family
- DRG 522 — HIP REPLACEMENT WITH PRINCIPAL DIAGNOSIS OF HIP FRACTURE WITHOUT MCC [DRG family]: “HIP REPLACEMENT WITH PRINCIPAL DIAGNOSIS OF HIP FRACTURE WITHOUT MCC — same CMS DRG family (521-522), split by severity.”