What does ICD-10 code O91.23 mean?

ICD-10 code O91.23 is the standardized code used for nonpurulent mastitis associated with lactation in medical records and coding systems.

When is ICD-10 code O91.23 used?

Doctors, hospitals, and insurers may use ICD-10 code O91.23 when recording nonpurulent mastitis associated with lactation in a standardized format.

Does ICD-10 code O91.23 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10BillableValid for clinical use

ICD-10 Code O91.23: Nonpurulent mastitis associated with lactation

Name: ICD-10 Code O91.23: Nonpurulent mastitis associated with lactation
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:28:32.635Z

O91.23 is a billable ICD-10 diagnosis code used to classify Nonpurulent mastitis associated with lactation in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Pregnancy, childbirth and the puerperium (O00-O9A).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Pregnancy, childbirth and the puerperium (O00-O9A).

When is it used?

May be used when a clinician documents nonpurulent mastitis associated with lactation in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter

15Pregnancy, childbirth and the puerperium (O00-O9A)

block

O85-O92Complications predominantly related to the puerperium

Official coding notes

Inclusion terms

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

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

ObstetricianGynecologist

Sibling codes

O91.21Nonpurulent mastitis associated with pregnancy O91.22Nonpurulent mastitis associated with the puerperiumbillable

Coding guidelines

Common synonyms

Nonpurulent mastitis associated with lactation

Frequently asked questions

Code details

CodeO91.23

SystemICD10

Display nameNonpurulent mastitis associated with lactation

ChapterPregnancy, childbirth and the puerperium (O00-O9A)

BlockComplications predominantly related to the puerperium

Flags

BillableYes

Valid clinical useYes

Source

SourceICD-10

Version2026-annual

Releaseannual

Year2026

Index terms

Matched terms

Mastitis(acute) (diffuse) (nonpuerperal) (subacute)Puerperal, puerperium(complicated by, complications)Puerperal, puerperium(complicated by, complications)Puerperal, puerperium(complicated by, complications)Puerperal, puerperium(complicated by, complications)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.