2026 ICD-10-CM Diagnosis Code P55.8Other hemolytic diseases of newborn
P55.8 is a billable ICD-10-CM diagnosis code for other hemolytic diseases of newborn. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 791, 793. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Hemolytic jaundice and perinatal jaundice.
For Medicare Advantage risk adjustment, P55.8 maps to CMS-HCC Category 109 (Acquired Hemolytic, Aplastic, and Sideroblastic Anemias) under the V28 model, adding a risk factor of about 1.144 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
P55.8 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Atypical isoimmunization of newborn
- Autoimmune hemolytic anemia mixed type
- Chronic hemolytic anemia
- Cold agglutinin disease due to Mycoplasma pneumonia
- Cold autoimmune hemolytic anemia
- Duffy isoimmunization of the newborn
- Hemolytic disease of fetus OR newborn due to isoimmunization
- Hemolytic disease of the newborn due to non-ABO, non-Rh isoimmunization
- Infection caused by Mycoplasma pneumoniae
- Isoimmunization from non-ABO, non-Rh blood-group incompatibility affecting pregnancy
- Kell isoimmunization of the newborn
- Kidd isoimmunization of the newborn
- Late anemia due to isoimmunization
- Neonatal anemia
- Neonatal autoimmune hemolytic anemia
- Neonatal jaundice due to glucose-6-phosphate dehydrogenase deficiency
- Warm autoimmune hemolytic anemia
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Isoimmunization NEC See Also: Incompatibility;
specified type NEC P55.8
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Hemolytic Jaundice
jaundice occurring as a result of red blood cell rupture.
Patient EducationClinical
Blood Disorders
Your blood is living tissue made up of liquid and solids. The liquid part, called plasma, is made of water, salts and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells and platelets.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert P55.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About P55.8Overview
What is the ICD-10 code for other hemolytic diseases of newborn?
The ICD-10-CM code for other hemolytic diseases of newborn is P55.8 (sometimes written as P558). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is P55.8 (Hemolytic disease of newborn) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other hemolytic diseases of newborn on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does P55.8 group to?
When other hemolytic diseases of newborn is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, with relative weights from 4.0590 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of P55.8?
Under the General Equivalence Mappings, other hemolytic diseases of newborn converts to ICD-9-CM 773.2 (NB hemolyt dis-isoim NEC). The mapping is approximate, so confirm the match fits the documentation.
What HCC is P55.8?
P55.8 (other hemolytic diseases of newborn) maps to CMS-HCC Category 109 (Acquired Hemolytic, Aplastic, and Sideroblastic Anemias), commonly written as HCC 109, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It does not map to any RxHCC in the Part D prescription drug model.
Does P55.8 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, P55.8 adds a risk adjustment factor of about 1.144 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.529 to 1.815 depending on the payment segment). HCC 109 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 109 category page.
