2026 ICD-10-CM Diagnosis Code A41.9Sepsis, unspecified organism

ICD-10-CM Codes›A00–B99›A30-A49›A41

ICD-10-CM A41.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A41.9 is a billable ICD-10-CM diagnosis code for sepsis, unspecified organism. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Septicemia.

Code Identity

ICD-10-CM Code
A41.9
Billable Status
Yes — Valid for Submission
Code Describes
Sepsis, unspecified organism
Short Description
Sepsis, unspecified organism
Same as the full description in the CMS dataset.
Parent Code
A41
Other sepsis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA41Other sepsis
This CodeA41.9Sepsis, unspecified organism

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute kidney injury due to sepsis
  • Acute lung injury
  • Acute respiratory distress
  • Antepartum septicemia
  • Bacterial sepsis
  • Chronic kidney disease due to systemic infection
  • Clinical infection
  • Clinical 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
  • Inflammation associated with vascular device
  • Left ventricular failure with sepsis
  • Lemierre syndrome
  • Lung injury with sepsis
  • Myocardial dysfunction with sepsis
  • Neutropenic sepsis
  • Postoperative sepsis
  • Pyemia
  • Respiratory distress
  • Right ventricular failure with sepsis
  • Sepsis
  • Sepsis associated with internal vascular access
  • Sepsis caused by central venous catheter in situ
  • Sepsis due to and following procedure
  • Sepsis due to oral infection
  • Sepsis due to urinary tract infection
  • Sepsis following infusion, injection, transfusion AND/OR vaccination
  • Sepsis in asplenic subject
  • Sepsis with acquired immunodeficiency syndrome
  • Sepsis with cutaneous manifestations
  • Sepsis without acute organ dysfunction
  • Sepsis without septic shock
  • Septic bronchitis
  • Septic splenitis
  • Septic thrombophlebitis
  • Septicemia associated with vascular access catheter
  • Systemic inflammatory response syndrome
  • Systemic inflammatory response syndrome without organ dysfunction
  • Thrombophlebitis of internal jugular vein
  • Thrombosis of internal jugular vein
  • Transient respiratory distress with sepsis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Septicemia NOS

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.

    • Disorder(of)
      • tubulo-interstitial (in)
        • sepsis
    • Glomerulonephritis
      • in (due to)
        • sepsis
    • Pyelonephritis
      • in (due to)
        • sepsis
    • Sepsis(generalized) (unspecified organism)
    • Sepsis(generalized) (unspecified organism)
      • cryptogenic
    • Sepsis(generalized) (unspecified organism)
      • gangrenous
    • Septicemia

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

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

Sepsis

Sepsis is your body's overactive and extreme response to an infection. Sepsis is a life-threatening medical emergency. Without quick treatment, it can lead to tissue damage, organ failure, and even death.

The full article covers:

  • What is sepsis?
  • What causes sepsis?
  • Who is more likely to develop sepsis?
  • What are the symptoms of sepsis?
  • What other problems can sepsis cause?
  • How is sepsis diagnosed?
  • What are the treatments for sepsis?
  • Can sepsis be prevented?

Read the full article at MedlinePlus

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

Convert A41.9 to ICD-9-CMHistory

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

ICD-9-CM
038.9 Septicemia NOS
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 A41.9Overview

Is A41.9 (Other sepsis) a billable code?

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

What MS-DRG does A41.9 group to?

When sepsis, unspecified organism 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 A41.9?

Under the General Equivalence Mappings, sepsis, unspecified organism converts to ICD-9-CM 038.9 (septicemia NOS) 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.