M12.5 vs M16.5
M12.5 and M16.5 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on M12.5
post-traumatic osteoarthritis of hip (M16.4-M16.5)
M12.5
Traumatic arthropathy
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M05-M14
M16.5
Unilateral post-traumatic osteoarthritis of hip
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M15-M19
Use when the record says
- Post-traumatic osteoarthritis of hip NOS
Indexed under
- Osteoarthritis › post-traumatic NEC › hip
- Osteoarthritis › hip › unilateral › post-traumatic
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027