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

Codes under O91 (Infections of breast associated with pregnancy, the puerperium and lactation). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.

Code	Description	Billable
O91.0	Infection of nipple associated with pregnancy, the puerperium and lactation	—
O91.01	Infection of nipple associated with pregnancy	—
O91.1	Abscess of breast associated with pregnancy, the puerperium and lactation	—
O91.02	Infection of nipple associated with the puerperium	✓
O91.2	Nonpurulent mastitis associated with pregnancy, the puerperium and lactation	—
O91.03	Infection of nipple associated with lactation	✓
O91.011	Infection of nipple associated with pregnancy, first trimester	✓
O91.11	Abscess of breast associated with pregnancy	—
O91.012	Infection of nipple associated with pregnancy, second trimester	✓
O91.12	Abscess of breast associated with the puerperium	✓
O91.013	Infection of nipple associated with pregnancy, third trimester	✓
O91.13	Abscess of breast associated with lactation	✓
O91.019	Infection of nipple associated with pregnancy, unspecified trimester	✓
O91.21	Nonpurulent mastitis associated with pregnancy	—
O91.22	Nonpurulent mastitis associated with the puerperium	✓
O91.23	Nonpurulent mastitis associated with lactation	✓
O91.111	Abscess of breast associated with pregnancy, first trimester	✓
O91.112	Abscess of breast associated with pregnancy, second trimester	✓
O91.113	Abscess of breast associated with pregnancy, third trimester	✓
O91.119	Abscess of breast associated with pregnancy, unspecified trimester	✓
O91.211	Nonpurulent mastitis associated with pregnancy, first trimester	✓
O91.212	Nonpurulent mastitis associated with pregnancy, second trimester	✓
O91.213	Nonpurulent mastitis associated with pregnancy, third trimester	✓
O91.219	Nonpurulent mastitis associated with pregnancy, unspecified trimester	✓

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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.

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