2026 ICD-10-CM Diagnosis Code P36.9Bacterial sepsis of newborn, unspecified
ICD-10-CM Codes›P00–P96›P35-P39›P36
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 2
- Not Chronic
P36.9 is a billable ICD-10-CM diagnosis code for bacterial sepsis of newborn, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 48 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections, Perinatal infections, and Septicemia.
For Medicare Advantage risk adjustment, P36.9 maps to CMS-HCC Category 2 (Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock) under the V28 model, adding a risk factor of about 0.500 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
P36.9 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.
- Acquired neutropenia
- Acquired neutropenia in newborn
- Acute kidney injury due to sepsis
- Acute lung injury
- Acute respiratory distress
- Bacterial sepsis
- Bacterial sepsis of newborn
- Clinical infection
- Clinical sepsis
- Early-onset neonatal sepsis
- Encephalopathy with sepsis
- Gastritis with sepsis
- Gastrointestinal hemorrhage with sepsis
- Gastrointestinal lesion with sepsis
- Gastrointestinal ulceration due to sepsis
- Indirect acute lung injury
- Infection of blood and lymphatic system
- Infection of bloodstream
- Late-onset neonatal sepsis
- Left ventricular failure with sepsis
- Lemierre syndrome
- Lung injury with sepsis
- Myocardial dysfunction with sepsis
- Perinatal sepsis
- Respiratory distress
- Right ventricular failure with sepsis
- Sepsis
- Sepsis due to and following procedure
- Sepsis due to urinary tract infection
- Sepsis of premature infant
- Sepsis of the newborn
- Sepsis with cutaneous manifestations
- Sepsis without acute organ dysfunction
- Sepsis without septic shock
- Septic thrombophlebitis
- Systemic inflammatory response syndrome
- Systemic inflammatory response syndrome without organ dysfunction
- Thrombophlebitis of internal jugular vein
- Thrombosis of internal jugular vein
- Transient neonatal neutropenia
- Transient neonatal neutropenia due to neonatal bacterial sepsis
- Transient respiratory distress with sepsis
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Lemierre Syndrome
a superinfection of the damaged oropharyngeal mucosa by fusobacterium necrophorum leading to the secondary septic thrombophlebitis of the internal jugular vein.Systemic Inflammatory Response Syndrome
a systemic inflammatory response to a variety of clinical insults, characterized by two or more of the following conditions: (1) fever >38 degrees c or hypothermia <36 degrees c; (2) tachycardia >90 beat/minute; (3) tachypnea >24 breaths/minute; (4) leukocytosis >12,000 cells/cubic mm or 10% immature forms. while usually related to infection, sirs can also be associated with noninfectious insults such as trauma; burns; or pancreatitis. if infection is involved, a patient with sirs is said to have sepsis.Acute Lung Injury
a condition of lung damage that is characterized by bilateral pulmonary infiltrates (pulmonary edema) rich in neutrophils, and in the absence of clinical heart failure. this can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).Transfusion-Related Acute Lung Injury
a rare but serious transfusion-related reaction in which fluid builds up in the lungs unrelated to excessively high infusion rate and/or volume (transfusion-associated circulatory overload). signs of transfusion-related acute lung injury include pulmonary secretions; hypotension; fever; dyspnea; tachypnea; tachycardia; and cyanosis.Burkholderia Infections
infections with bacteria of the genus burkholderia.Neonatal Sepsis
blood infection that occurs in an infant younger than 90 days old. early-onset sepsis is seen in the first week of life and most often appears within 24 hours of birth. late-onset occurs after 1 week and before 3 months of age.Pregnancy Complications, Infectious
the co-occurrence of pregnancy and an infection. the infection may precede or follow fertilization.Puerperal Infection
an infection occurring in puerperium, the period of 6-8 weeks after giving birth.Sepsis
systemic inflammatory response syndrome with a proven or suspected infectious etiology. when sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. when sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock.Sepsis-Associated Encephalopathy
acute neurological dysfunction during severe sepsis in the absence of direct brain infection characterized by systemic inflammation and blood brain barrier perturbation.Burkholderia
a genus of gram-negative, aerobic, rod-shaped bacteria originally classified as members of the pseudomonadaceae.Clinical Infection
an infection that exhibits features or characteristics that exceed an agreed-upon threshold among subject matter experts, which warrants attention or treatment.Infectious Disorder|Clinical Infection|ID|INFECTION|Infection|Infection|Infectious|Infectious Disease|Infectious Disease|Infectious Disease|Infectious Diseases and Manifestations|Unspecified Infection|infection
a disorder resulting from the presence and activity of a microbial, viral, fungal, or parasitic agent. it can be transmitted by direct or indirect contact.Subclinical Infection|Asymptomatic Infection|Inapparent Infection
infection associated with no detectable symptoms but caused by microorganisms capable of producing easily recognizable diseases, such a poliomyelitis or mumps.
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 P36.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About P36.9Overview
What is the ICD-10 code for bacterial sepsis of newborn, unspecified?
The ICD-10-CM code for bacterial sepsis of newborn, unspecified is P36.9 (sometimes written as P369). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is P36.9 (Bacterial sepsis of newborn) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report bacterial sepsis of newborn, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does P36.9 group to?
When bacterial sepsis of newborn, unspecified 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.
Is P36.9 a CC or MCC?
CMS lists P36.9 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 48 closely related codes in its exclusion list.
What is the ICD-9 equivalent of P36.9?
Under the General Equivalence Mappings, bacterial sepsis of newborn, unspecified converts to ICD-9-CM 771.81 (NB septicemia [sepsis]). The mapping is approximate, so confirm the match fits the documentation.
What HCC is P36.9?
P36.9 (bacterial sepsis of newborn, unspecified) maps to CMS-HCC Category 2 (Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock), commonly written as HCC 2, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 2 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does P36.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, P36.9 adds a risk adjustment factor of about 0.500 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.447 to 0.780 depending on the payment segment). HCC 2 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 2 category page.
