ICD-10 Code M05.45 – Rheumatoid myopathy with rheumatoid arthritis of hip (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.45 – Rheumatoid myopathy with rheumatoid arthritis of hip
What it is
This code identifies rheumatoid arthritis affecting the hip with associated rheumatoid myopathy. Use it when the record documents both the inflammatory arthritis and muscle involvement tied to the same rheumatoid condition.
Clinical signs
Typical findings include hip pain, stiffness, reduced range of motion, and weakness related to rheumatoid muscle involvement. Clinical features vary; refer to documentation.
When to use this code
Use M05.45 when the provider clearly documents rheumatoid arthritis of the hip and rheumatoid myopathy together. It is appropriate when the hip is the specified joint and the muscle disorder is part of the rheumatoid disease picture.
Do not assume myopathy from generalized weakness alone. Check documentation for the exact joint, laterality if applicable, and any stated rheumatoid factor or seropositive status.
Do not use for
Do not use this code for hip arthritis without rheumatoid myopathy, or for myopathy from another cause. Check documentation if the record does not clearly link both conditions.
Coding tip
Assign this code only when both the rheumatoid hip involvement and myopathy are explicitly documented together.