2026 ICD-10-CM Diagnosis Code A41.51Sepsis due to Escherichia coli [E. coli]

ICD-10-CM Codes›A00–B99›A30-A49›A41

ICD-10-CM A41.51
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A41.51 is a billable ICD-10-CM diagnosis code for sepsis due to Escherichia coli [E. coli]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 870 through 872, 974 through 976. Coders also document this condition as sepsis caused by coliform bacteria. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Septicemia.

Code Identity

ICD-10-CM Code
A41.51
Billable Status
Yes — Valid for Submission
Code Describes
Sepsis due to Escherichia coli [E. coli]
Short Description
Sepsis due to Escherichia coli [E. coli]
Same as the full description in the CMS dataset.
Parent Code
A41.5
Sepsis due to other Gram-negative organisms

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA41Other sepsis
This CodeA41.51Sepsis due to Escherichia coli [E. coli]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Sepsis caused by coliform bacteria
  • Sepsis caused by Escherichia coli

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.

    • Colibacillosis
      • generalized
    • Infection, infected, infective(opportunistic)
      • Escherichia (E.) coli NEC
        • generalized
    • Sepsis(generalized) (unspecified organism)
      • Escherichia coli (E. coli)

Clinical ClassificationClinical

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

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

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 A41.51 to ICD-9-CMHistory

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

ICD-9-CM
038.42 E coli septicemia
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
995.91 Sepsis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 A41.51Overview

Is A41.51 (Sepsis due to other Gram-negative organisms) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sepsis due to Escherichia coli [E. coli] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A41.51 group to?

When sepsis due to Escherichia coli [E. coli] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 870, 871, 872, 974, 975, 976, with relative weights from 0.8945 to 6.9118 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A41.51?

Under the General Equivalence Mappings, sepsis due to Escherichia coli [E. coli] converts to ICD-9-CM 038.42 (e coli septicemia) and 995.91 (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.