Excludes1 pair

M54- vs M79.3

M54 and M79.3 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 M79.3
neck and back panniculitis (M54.0-)
M54

Dorsalgia

Not billable
Chapter 13
Diseases of the musculoskeletal system and connective tissue
Section
M50-M54
M79.3

Panniculitis, unspecified

BillableUnspecified
Chapter 13
Diseases of the musculoskeletal system and connective tissue
Section
M70-M79
Indexed under
  • Lipodermatosclerosis
  • Panniculitis (nodular) (nonsuppurative)

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