M22.4 vs M94.2
M22.4 and M94.2 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 M94.2
chondromalacia patellae (M22.4)
M22.4
Chondromalacia patellae
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M20-M25
Indexed under
- Chondromalacia › patella (systemic)
- Chondromalacia › knee › patella (systemic)
- Softening › cartilage › patella
M94.2
Chondromalacia
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M91-M94
Indexed under
- Softening › cartilage
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