M12.5 vs M18.3
M12.5 (Traumatic arthropathy) compared with M18.3 (Unilateral post-traumatic osteoarthritis of first carpometacarpal joint), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. M12.5 carries an Excludes1 note covering M18.3: “post-traumatic osteoarthritis of first carpometacarpal joint (M18.2-M18.3)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| M12.5Traumatic arthropathy | M18.3Unilateral post-traumatic osteoarthritis of first carpometacarpal joint | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Traumatic arthropathy is a non-billable ICD-10-CM category code (M12.5). | Unilateral post-traumatic osteoarthritis of first carpometacarpal joint is a non-billable ICD-10-CM category code (M18.3). |
| Includes | — | Post-traumatic osteoarthritis of first carpometacarpal joint NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources