ICD-10-CM 2027
ICD-10 code for congenital peritonitis
From the official ICD-10-CM alphabetic index entry “Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) › congenital”. Page updated September 29, 2026.
About coding congenital peritonitis
The ICD-10-CM code for congenital peritonitis is P78.1 (Other neonatal peritonitis).
Within P78, choose P78.1 (Other neonatal peritonitis) only when documentation doesn't support a more specific option: perinatal intestinal perforation (P78.0), neonatal hematemesis and melena due to swallowed maternal blood (P78.2), noninfective neonatal diarrhea (P78.3), other specified perinatal digestive system disorders (P78.8) and perinatal digestive system disorder, unspecified (P78.9).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 794 (Neonate with Other Significant Problems, relative weight 1.4935), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about congenital peritonitis ICD-10 codes
What is the ICD-10 code for congenital peritonitis?
- P78.1 — Other neonatal peritonitis.
Is P78.1 billable?
- Yes. P78.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can P78.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict P78.1 as a principal diagnosis.
Is P78.1 a CC or MCC?
- No. P78.1 is neither a CC nor an MCC under MS-DRG v44.0.