Excludes1 pair

M95.5 vs O33-

M95.5 and O33 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 M95.5
maternal care for known or suspected disproportion (O33.-)
M95.5

Acquired deformity of pelvis

Billable
Chapter 13
Diseases of the musculoskeletal system and connective tissue
Section
M95
Indexed under
  • Nägele's pelvis
  • Platypelloid pelvis
  • Contraction, contracture, contracted › pelvis (acquired) (general)
  • Deformity › ilium (acquired)
  • Deformity › ischium (acquired)
O33

Maternal care for disproportion

Not billable
Chapter 15
Pregnancy, childbirth and the puerperium
Section
O30-O48
Use when the record says
  • the listed conditions as a reason for observation, hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor

These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.

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