M22.9Unspecified disorder of patella

M22.9 is the ICD-10-CM diagnosis code for unspecified disorder of patella. It belongs to category M22 (disorder of patella), block M20-M25 (other joint disorders) 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 3 subcodes must be used instead.

Within M22, choose M22.9 (Unspecified disorder of patella) only when documentation doesn't support a more specific option: recurrent dislocation of patella (M22.0), recurrent subluxation of patella (M22.1), Patellofemoral disorders (M22.2), other derangements of patella (M22.3), Chondromalacia patellae (M22.4) and other disorders of patella (M22.8).

To report this condition, pick the subcode that matches the documentation: M22.90 (unspecified knee), M22.91 (right knee) and M22.92 (left knee).

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