O91.23

Nonpurulent mastitis associated with lactation

Billable code

This code does not map to a risk-adjusting HCC in the loaded models.

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

This code · O91.23
Synonyms

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

Inherited from O91Infect of breast assoc w pregnancy, the puerp and lactation
Use additional

code to identify infection

Inherited from O85-O92Complications predominantly related to the puerperium
Excludes 2

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

Inherited from chapter 15Pregnancy, childbirth and the puerperium
Excludes 1

supervision of normal pregnancy (Z34.-)

Excludes 2

mental and behavioral disorders associated with the puerperium (F53.-) obstetrical tetanus (A34) postpartum necrosis of pituitary gland (E23.0) puerperal osteomalacia (M83.0)

Use additional

code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Note

CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes) Trimesters are counted from the first day of the last menstrual period. They are defined as follows: 1st trimester- less than 14 weeks 0 days 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days 3rd trimester- 28 weeks 0 days until delivery

Official Guidelines for O91.23

FY 2026 ›

Sections that reference O91.23

Sections whose FY 2026 text names O91.23, its O91 category, or a range containing it — the chapter guidance above is the authoritative source.