ICD-10-CM 2027 diagnosis code

O91Infections of breast associated with pregnancy, the puerperium and lactation

Not billable — use a more specific code

O91 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.Short description: Infect of breast assoc w pregnancy, the puerp and lactation

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O91

O91 is the ICD-10-CM diagnosis code for infections of breast associated with pregnancy, the puerperium and lactation. It belongs to block O85-O92 (complications predominantly related to the puerperium) and chapter 15 (pregnancy, childbirth and the puerperium). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: O91.0 (lactation), O91.1 (lactation) and O91.2 (lactation).

Use an additional code to identify infection.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under O91

Coding notes

Use additional codeAdd a secondary code to fully describe the condition

code to identify infection

Notes that apply from higher levels

Instructions written at a parent level also apply to O91.

Broader instructions also apply from O85-O92 Complications predominantly related to the puerperium and Chapter 15: Pregnancy, childbirth and the puerperium.

Codes whose notes reference O91

N61Excludes1

Code history

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2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about O91

Is O91 billable?: No. O91 is a header code. Report one of its more specific subcodes instead.