Other specified arthritis, multiple sites

This code signifies an inflammatory joint condition affecting multiple anatomical locations that does not fit into more specific categories of arthritis. It encompasses various forms of arthritis that are clearly identified by the physician but lack a dedicated ICD-10-CM code for their specific type and multi-site involvement.

Apply this code when documentation specifies a type of arthritis (e.g., psoriatic arthritis, reactive arthritis, or other less common forms) impacting more than one joint region, and a more precise code for that specific arthritis with multi-site involvement is unavailable. This code is appropriate when the physician's diagnosis explicitly states "other specified arthritis, multiple sites" or similar phrasing.

• Ensure the medical record clearly identifies the specific type of arthritis and confirms involvement of multiple joint sites.
• Avoid using this code if a more specific ICD-10-CM code exists for the documented type of arthritis affecting multiple sites (e.g., rheumatoid arthritis, polyosteoarthritis).
• Always review the entire M13 category to ensure no more precise code is available before assigning this "other specified" code.