550
SEPTIC ARTHRITIS WITHOUT CC/MCC
MS-DRG 550 groups Medicare inpatient hospital stays for: SEPTIC ARTHRITIS WITHOUT CC/MCC. This is a medical 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 | Medical |
| Severity Level | None |
| Relative Weight | 0.8741 |
| Relative Weight (10% Cap Applied) | 0.8741 |
| Geometric Mean Length of Stay | 3.1 days |
| Arithmetic Mean Length of Stay | 3.7 days |
| Post-Acute Transfer DRG | No |
| Special Pay Transfer DRG | No |
Defining Codes (FY2026)
155 diagnosis codes can drive assignment here: A02.23, A18.02, A18.09, A39.83, A39.84, A54.40, A54.42, A54.43, A54.49, A66.6, M00.00, M00.011 and 143 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 550 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 (155)
- A02.23 — Salmonella arthritis [Grouper diagnosis]
- A18.02 — Tuberculous arthritis of other joints [Grouper diagnosis]
- A18.09 — Other musculoskeletal tuberculosis [Grouper diagnosis]
- A39.83 — Meningococcal arthritis [Grouper diagnosis]
- A39.84 — Postmeningococcal arthritis [Grouper diagnosis]
- A54.40 — Gonococcal infection of musculoskeletal system, unspecified [Grouper diagnosis]
- A54.42 — Gonococcal arthritis [Grouper diagnosis]
- A54.43 — Gonococcal osteomyelitis [Grouper diagnosis]
- and 147 more