2027 ICD-10-CM Diagnosis Code P36.4Sepsis of newborn due to Escherichia coli
ICD-10-CM Codes›P00–P96›P35-P39›P36
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 2
- Not Chronic
P36.4 is a billable ICD-10-CM diagnosis code for sepsis of newborn due to Escherichia coli. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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. 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.
For Medicare Advantage risk adjustment, P36.4 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 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
P36.4 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 2027.
Source: CMS Payment Year 2027 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.
- Bacterial sepsis of newborn
- Neonatal sepsis caused by Escherichia coli
- Perinatal sepsis
- Perinatal sepsis caused by Escherichia coli
- Sepsis caused by coliform bacteria
- Sepsis caused by Escherichia coli
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to P36.4: its own notes plus those printed at P36, block P35-P39, and Chapter 16. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- congenital sepsis
- conditions that have their origin in the fetal or perinatal period (before birth through the first 28 days after birth) even if morbidity occurs later
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- asymptomatic human immunodeficiency virus [HIV] infection status (Z21)
- congenital gonococcal infection (A54.-)
- congenital pneumonia (P23.-)
- congenital syphilis (A50.-)
- human immunodeficiency virus [HIV] disease (B20)
- infant botulism (A48.51)
- infectious diseases not specific to the perinatal period (A00-B99, J09, J10.-)
- intestinal infectious disease (A00-A09)
- laboratory evidence of human immunodeficiency virus [HIV] (R75)
- tetanus neonatorum (A33)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
Notes
General instructions on how these codes are used.
- Codes from this chapter are for use on newborn records only, never on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name P36.4, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming P36.4: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming P36.4: its condition is not part of those codes, and both may be reported when the patient has both.
- Chapter 1 (A00-B99) Certain infectious and parasitic diseases
- P00.2 Newborn affected by maternal infectious and parasitic diseases
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.
Patient EducationClinical
E. coli Infections
E. coli is the name of a type of bacteria that lives in your intestines. Most types of E. coli are harmless. However, some types can make you sick and cause diarrhea. One type causes travelers' diarrhea. The worst type of E. coli causes bloody diarrhea, and can sometimes cause kidney failure and even death.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert P36.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About P36.4Overview
What is the ICD-10 code for sepsis of newborn due to Escherichia coli?
The ICD-10-CM code for sepsis of newborn due to Escherichia coli is P36.4 (sometimes written as P364). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is P36.4 (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 Escherichia coli on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does P36.4 group to?
When sepsis of newborn due to Escherichia coli is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, with relative weights from 4.1073 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is P36.4 a CC or MCC?
CMS lists P36.4 as an MCC (major complication or comorbidity) for FY 2027. 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.
Does P36.4 need an additional code?
When the condition applies, yes. The Use Additional Code note at P36, which applies to P36.4, reads: code(s), if applicable, to identify severe sepsis (R65.2-) and associated acute organ dysfunction(s). The additional code is reported after P36.4.
What HCC is P36.4?
P36.4 (sepsis of newborn due to Escherichia coli) 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 2027. 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 P36.4 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, P36.4 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.
