M35.6 vs M79
M35.6 and M79 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 M35.6
panniculitis NOS (M79.3-)
M35.6
Relapsing panniculitis [Weber-Christian]
Billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M30-M36
Indexed under
- Christian-Weber disease
- Weber-Christian disease
- Panniculitis › relapsing (nodular) (nonsuppurative)
M79
Other and unspecified soft tissue disorders, not elsewhere classified
Not billable
- Chapter 13
- Diseases of the musculoskeletal system and connective tissue
- Section
- M70-M79
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