Excludes1 pair

M35.6 vs M54.0-

M35.6 and M54.0 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on M54.0
relapsing [Weber-Christian] panniculitis (M35.6)
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
M54.0

Panniculitis affecting regions of neck and back

Not billable
Chapter 13
Diseases of the musculoskeletal system and connective tissue
Section
M50-M54

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