O91 – Infections of breast associated with pregnancy, the puerperium and lactation

ICD-10-CM 2027 diagnosis code · Complications predominantly related to the puerperium

Non-billable header

ICD-10-CM code O91

Code: O91 (claims format: O91)
Description: Infections of breast associated with pregnancy, the puerperium and lactation
Short description: Infect of breast assoc w pregnancy, the puerp and lactation
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 15. Pregnancy, childbirth and the puerperium (O00-O9A)
Block: O85-O92 Complications predominantly related to the puerperium

Billable codes under O91

O91 is a header code and cannot be used on claims. Choose the most specific code:

O91.0 – Infection of nipple associated with pregnancy, the puerperium and lactationHeader (more codes below)
O91.1 – Abscess of breast associated with pregnancy, the puerperium and lactationHeader (more codes below)
O91.2 – Nonpurulent mastitis associated with pregnancy, the puerperium and lactationHeader (more codes below)

Notes for O91

Use additional code:

code to identify infection

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block O85-O92

Excludes2 (not included here):

mental and behavioral disorders associated with the puerperium (F53.-)
obstetrical tetanus (A34)
puerperal osteomalacia (M83.0)

Frequently asked questions

What is ICD-10 code O91?

O91 is the ICD-10-CM code for infections of breast associated with pregnancy, the puerperium and lactation, in the block O85-O92 (Complications predominantly related to the puerperium).

Is O91 a billable code?

No. O91 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.