ICDcodes.org
FY2027

O92 vs Z39.1

O92 and Z39.1 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 Z39.1
disorders of lactation (O92.-)
O92

Other disorders of breast and disorders of lactation associated with pregnancy and the puerperium

Not billable
Chapter 15
Pregnancy, childbirth and the puerperium
Section
O85-O92
Z39.1

Encounter for care and examination of lactating mother

Billable
Chapter 21
Factors influencing health status and contact with health services
Section
Z30-Z39
Use when the record says
  • Encounter for supervision of lactation
Indexed under
  • Care › lactating mother (of) (for) (following)
  • Examination › lactating mother (for) (following) (general) (of) (routine)
  • Lactation, lactating › mother (breast) (puerperal, postpartum)
  • Supervision › lactation (of)

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