2026 ICD-10-CM Diagnosis Code P55.0Rh isoimmunization of newborn

ICD-10-CM Codes›P00–P96›P50-P61›P55

ICD-10-CM P55.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

P55.0 is a billable ICD-10-CM diagnosis code for rh isoimmunization of newborn. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as hemolytic disease of fetus OR newborn due to RhD isoimmunization. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Hemolytic jaundice and perinatal jaundice.

Code Identity

ICD-10-CM Code
P55.0
Billable Status
Yes — Valid for Submission
Code Describes
Rh isoimmunization of newborn
Short Description
Rh isoimmunization of newborn
Same as the full description in the CMS dataset.
Parent Code
P55
Hemolytic disease of newborn

Code Classification

ChapterP00–P96Certain conditions originating in the perinatal period
SectionP50-P61Hemorrhagic and hematological disorders of newborn
CategoryP55Hemolytic disease of newborn
This CodeP55.0Rh isoimmunization of newborn

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Hemolytic disease of fetus OR newborn due to RhD isoimmunization
  • Rhesus isoimmunization due to anti-c
  • Rhesus isoimmunization due to anti-Cw
  • Rhesus isoimmunization due to anti-D
  • Rhesus isoimmunization due to anti-E

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.

    • Anemia(essential) (general) (hemoglobin deficiency) (infantile) (primary) (profound)
      • newborn
        • due to
          • Rh (antibodies, isoimmunization, maternal/fetal incompatibility)
    • Antibodies, maternal(blood group)
      • anti-D
        • newborn
    • Disease, diseased
      • hemolytic (newborn)
        • due to or with
          • incompatibility
            • Rh (blood group) (factor)
    • Disease, diseased
      • hemolytic (newborn)
        • due to or with
          • Rh negative mother
    • Erythroblastosis(fetalis) (newborn)
      • due to
        • Rh (antibodies) (incompatibility) (isoimmunization)
    • Icterus
      • gravis, newborn
    • Incompatibility
      • Rh (blood group) (factor)
        • newborn
    • Isoimmunization NEC
      • newborn
        • Rhesus (Rh) factor
    • Jaundice(yellow)
      • newborn
        • due to or associated with
          • hemolytic disease
            • Rh isoimmunization
    • Jaundice(yellow)
      • newborn
        • due to or associated with
          • Rh
            • antibodies
    • Jaundice(yellow)
      • newborn
        • due to or associated with
          • Rh
            • incompatibility, maternal/fetal
    • Jaundice(yellow)
      • newborn
        • due to or associated with
          • Rh
            • isoimmunization
    • Rh(factor)
      • hemolytic disease (newborn)
    • Rh(factor)
      • incompatibility, immunization or sensitization
        • newborn
    • Rh(factor)
      • negative mother affecting newborn

Clinical ClassificationClinical

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

CCSR PNL007
Hemolytic jaundice and perinatal jaundice
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Rh Incompatibility

There are four major blood types: A, B, O, and AB. The types are based on substances found on your blood cells. Your blood type also has a positive or negative sign. This is called Rh factor, which is a protein. If your blood cells have this protein, you are Rh-positive. If you don't, you are Rh-negative.

The full article covers:

  • What is the Rh factor?
  • What is Rh incompatibility?
  • How is Rh incompatibility diagnosed?
  • How is Rh incompatibility treated?
  • Can Rh incompatibility be prevented?

Read the full article at MedlinePlus

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

Convert P55.0 to ICD-9-CMHistory

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

ICD-9-CM
773.0 NB hemolyt dis:rh isoimm
Exact Match The mapping is direct, with no qualifiers.

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 P55.0Overview

Is P55.0 (Hemolytic disease of newborn) a billable code?

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

What is the ICD-9 equivalent of P55.0?

Under the General Equivalence Mappings, rh isoimmunization of newborn converts to ICD-9-CM 773.0 (NB hemolyt dis:rh isoimm). The mapping is a direct match.

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.