ICD-10 Code M05.422 – Rheumatoid myopathy with rheumatoid arthritis of left elbow (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.422 – Rheumatoid myopathy with rheumatoid arthritis of left elbow
What it is
This code identifies rheumatoid arthritis affecting the left elbow with associated rheumatoid myopathy. It means the joint disease and muscle involvement are documented together on the left side.
Clinical signs
Typical findings include inflammatory elbow pain, swelling, stiffness, and reduced range of motion, plus muscle weakness related to rheumatoid myopathy. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents rheumatoid arthritis of the left elbow and specifically links rheumatoid myopathy to the same condition. It supports coding of both the joint and muscle involvement on the left side. If laterality or myopathy is not stated, check documentation.
Do not use for
Do not use this code for rheumatoid arthritis without documented myopathy, or for muscle weakness from another cause. Also avoid it if the affected elbow is not clearly identified as left.
Coding tip
Confirm both the rheumatoid myopathy and left elbow laterality in the record before assigning M05.422.