M19Other and unspecified osteoarthritis

M19 is the ICD-10-CM diagnosis code for other and unspecified osteoarthritis. It belongs to block M15-M19 (osteoarthritis) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: M19.0 (joints), M19.1 (joints), M19.2 (joints) and M19.9 (site).

Don't report M19 together with the conditions in its Excludes1 note: polyarthritis (M15.-).

The conditions in its Excludes2 note aren't part of M19, but may be coded alongside it if the patient has both: arthrosis of spine (M47.-), hallux rigidus (M20.2) and osteoarthritis of spine (M47.-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.