O91.23 – Nonpurulent mastitis associated with lactation

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

Billable code

ICD-10-CM code O91.23

Code: O91.23 (claims format: O9123)
Description: Nonpurulent mastitis associated with lactation
Billable: Yes – valid for HIPAA-covered transactions
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
Parent codes: O91 › O91.2

Notes for O91.23

Applicable to:

Interstitial mastitis associated with lactation
Lymphangitis of breast associated with lactation
Mastitis NOS associated with lactation
Parenchymatous mastitis associated with lactation

Notes inherited from parent codes

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

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

Use additional code:

code to identify infection

Block O85-O92

Excludes2 (not included here):

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

Index terms for O91.23

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in O91.2

Frequently asked questions

What is ICD-10 code O91.23?

O91.23 is the ICD-10-CM code for nonpurulent mastitis associated with lactation, in the block O85-O92 (Complications predominantly related to the puerperium).

Is O91.23 a billable code?

Yes. O91.23 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does O91.23 belong to?

It belongs to category O91 – Infections of breast associated with pregnancy, the puerperium and lactation.

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.