Rheumatoid myopathy w rheumatoid arthritis of unsp ank/ft

This code signifies muscle involvement (myopathy) directly attributable to rheumatoid arthritis, specifically affecting an unspecified ankle and foot. It indicates a systemic autoimmune inflammatory process manifesting with both joint and muscular pathology in the lower extremity.

Apply this code when documentation clearly states rheumatoid myopathy in the context of rheumatoid arthritis impacting the ankle and/or foot, without specifying laterality. This diagnosis requires physician documentation explicitly linking the myopathy to the rheumatoid arthritis.

• Ensure the documentation specifies "rheumatoid myopathy" and not just general muscle pain or weakness.
• If laterality (right or left ankle/foot) is documented, a more specific code (M05.471 or M05.472) should be used.
• Always sequence the underlying rheumatoid arthritis code (e.g., M05.xx) first, followed by this code for the manifestation.