2026 ICD-10-CM Diagnosis Code P36.5Sepsis of newborn due to anaerobes

ICD-10-CM Codes›P00–P96›P35-P39›P36

ICD-10-CM P36.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P36.5 is a billable ICD-10-CM diagnosis code for sepsis of newborn due to anaerobes. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as bacterial sepsis of newborn. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections, Perinatal infections, and Septicemia.

Code Identity

ICD-10-CM Code
P36.5
Billable Status
Yes — Valid for Submission
Code Describes
Sepsis of newborn due to anaerobes
Short Description
Sepsis of newborn due to anaerobes
Same as the full description in the CMS dataset.
Parent Code
P36
Bacterial sepsis of newborn

Code Classification

ChapterP00–P96Certain conditions originating in the perinatal period
SectionP35-P39Infections specific to the perinatal period
CategoryP36Bacterial sepsis of newborn
This CodeP36.5Sepsis of newborn due to anaerobes

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bacterial sepsis of newborn
  • Early-onset neonatal sepsis
  • Perinatal sepsis
  • Sepsis caused by anaerobic bacteria
  • Sepsis caused by Bacteroides
  • Sepsis caused by Peptostreptococcus
  • Sepsis of newborn caused by anaerobes

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Newborn(infant) (liveborn) (singleton)
      • sepsis (congenital)
        • due to
          • anaerobes NEC
    • Sepsis(generalized) (unspecified organism)
      • newborn
        • due to
          • anaerobes NEC

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR PNL009
Perinatal infections
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF002
Septicemia
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Bacterial Infections

Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.

The full article covers:

  • What are bacteria?
  • How do bacterial infections spread?
  • What are the treatments for bacterial infections?
  • Can bacterial infections be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert P36.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
771.81 NB septicemia [sepsis]
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About P36.5Overview

Is P36.5 (Bacterial sepsis of newborn) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sepsis of newborn due to anaerobes on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of P36.5?

Under the General Equivalence Mappings, sepsis of newborn due to anaerobes converts to ICD-9-CM 771.81 (NB septicemia [sepsis]). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.