ICD-10 Code for Mastitis
Also indexed as (acute) (diffuse) (nonpuerperal) (subacute)
The ICD-10-CM code for mastitis is N61.0 — Mastitis without abscess. This is the code the Alphabetic Index gives for mastitis with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
Billable
Which mastitis code should you use?
The Alphabetic Index lists 11 codes under Mastitis. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
Mastitis infective
| newborn | P39.0 | Neonatal infective mastitis |
Mastitis neonatal
| infective | P39.0 | Neonatal infective mastitis |
Mastitis obstetric
| associated with › lactation | O91.23 | Nonpurulent mastitis associated with lactation | |
| associated with › pregnancy | O91.21 | Nonpurulent mastitis associated with pregnancy | not billable |
| associated with › puerperium | O91.22 | Nonpurulent mastitis associated with the puerperium | |
| purulent › associated with › lactation | O91.13 | Abscess of breast associated with lactation | |
| purulent › associated with › pregnancy | O91.11 | Abscess of breast associated with pregnancy | not billable |
| purulent › associated with › puerperium | O91.12 | Abscess of breast associated with the puerperium |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources