ICD-10-CM 2027
ICD-10 code for mastitis newborn
From the official ICD-10-CM alphabetic index entry “Newborn (infant) (liveborn) (singleton) › mastitis”. Page updated September 29, 2026.
About coding mastitis newborn
The ICD-10-CM code for mastitis newborn is P39.0 (Neonatal infective mastitis). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on P39.0.
Within P39 (other infections specific to the perinatal period), P39.0 is specifically for neonatal infective mastitis. Related codes cover neonatal conjunctivitis and dacryocystitis (P39.1), Intra-amniotic infection affecting newborn, not elsewhere classified (P39.2), neonatal urinary tract infection (P39.3), neonatal skin infection (P39.4), other specified infections specific to the perinatal period (P39.8) and infection specific to the perinatal period, unspecified (P39.9).
Don't report P39.0 together with the conditions in its Excludes1 note: breast engorgement of newborn (P83.4) and noninfective mastitis of newborn (P83.4).
Use an additional code to identify organism or specific infection.
More specific mastitis newborn codes (official index)
Don't confuse with (Excludes1 for P39.0)
Common questions about mastitis newborn ICD-10 codes
What is the ICD-10 code for mastitis newborn?
- P39.0 — Neonatal infective mastitis. More specific codes apply when the documentation supports them: P39.0, P83.4.
What is the ICD-10 code for infective mastitis newborn?
- P39.0 — Neonatal infective mastitis.
What is the ICD-10 code for noninfective mastitis newborn?
- P83.4 — Breast engorgement of newborn.
Is P39.0 billable?
- Yes. P39.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can P39.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict P39.0 as a principal diagnosis.
Is P39.0 a CC or MCC?
- P39.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.