M05.40
BillableRheumatoid myopathy with rheumatoid arthritis of unspecified site
HCC Category Mapping
V28HCC 93 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.175V24HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.307ESRDHCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000RxHCCHCC 83 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000What This Code Means
Muscle weakness and inflammation (myopathy) caused by rheumatoid arthritis when the specific joint location is not identified.
Coding Tips
- •Use this code only when the site of rheumatoid arthritis is unspecified or unknown
- •Document the presence of myopathy (muscle involvement) in addition to the arthritis diagnosis
Clinical Significance
This diagnosis represents rheumatoid arthritis complicated by muscle weakness and inflammation (myopathy) when the specific joint site is not documented. Rheumatoid myopathy indicates systemic disease progression beyond joint involvement, affecting muscle tissue and requiring aggressive disease-modifying therapy and monitoring for functional decline and disability.
Documentation Requirements
- ✓Confirmed diagnosis of rheumatoid arthritis with positive serology (RF or anti-CCP)
- ✓Clinical evidence of muscle weakness, atrophy, or inflammatory myopathy
- ✓Documentation of muscle enzyme elevation (CK, aldolase) or muscle biopsy findings
- ✓Electromyography or nerve conduction studies showing myopathy
- ✓Assessment of functional limitations related to muscle weakness
- ✓Laboratory evidence of systemic inflammation (elevated ESR, CRP)
- ✓Documentation of chronicity and ongoing disease activity
- ✓Treatment with DMARDs or biologic agents
Commonly Confused Codes
M05.41-M05.49 — Rheumatoid myopathy with specific joint site documentation (more specific when known)G72.9 — Myopathy, unspecified (not related to rheumatoid arthritis)M60.9 — Myositis, unspecified (different inflammatory muscle condition)M06.9 — Rheumatoid arthritis, unspecified (no myopathy involvement documented)