2026 ICD-10-CM Diagnosis Code B44.0Invasive pulmonary aspergillosis

ICD-10-CM Codes›A00–B99›B35-B49›B44

ICD-10-CM B44.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B44.0 is a billable ICD-10-CM diagnosis code for invasive pulmonary aspergillosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 177 through 179. Coders also document this condition as invasive aspergillosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections and Other specified and unspecified lower respiratory disease.

Code Identity

ICD-10-CM Code
B44.0
Billable Status
Yes — Valid for Submission
Code Describes
Invasive pulmonary aspergillosis
Short Description
Invasive pulmonary aspergillosis
Same as the full description in the CMS dataset.
Parent Code
B44
Aspergillosis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB35-B49Mycoses
CategoryB44Aspergillosis
This CodeB44.0Invasive pulmonary aspergillosis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Invasive aspergillosis
  • Invasive pulmonary aspergillosis
  • Pulmonary aspergillosis
  • Subacute invasive pulmonary aspergillosis

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.

    • Aspergillosis(with pneumonia)
      • pulmonary NEC
        • invasive

Clinical ClassificationClinical

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

CCSR INF004
Fungal infections
Default principal diagnosis: inpatient No · outpatient No
CCSR RSP016
Other specified and unspecified lower respiratory disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Invasive Pulmonary Aspergillosis

    lung infections with the invasive forms of aspergillus, usually after surgery, transplantation, prolonged neutropenia or treatment with high-doses of corticosteroids. invasive pulmonary aspergillosis can progress to chronic necrotizing pulmonary aspergillosis or hematogenous spread to other organs.

  • Pulmonary Aspergillosis

    infections of the respiratory tract with fungi of the genus aspergillus.

  • Aspergillus

    a genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family trichocomaceae.

Patient EducationClinical

Aspergillosis

Aspergillosis is a disease caused by a fungus (or mold) called Aspergillus. The fungus is very common in both indoors and outdoors. Most people breathe in the spores of the fungus every day without being affected. But some people get the disease. It usually occurs in people with lung diseases or weakened immune systems.

Read the full article at MedlinePlus

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

Convert B44.0 to ICD-9-CMHistory

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

ICD-9-CM
117.3 Aspergillosis
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
484.6 Pneum in aspergillosis
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 B44.0Overview

Is B44.0 (Aspergillosis) a billable code?

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

What MS-DRG does B44.0 group to?

When invasive pulmonary aspergillosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 177, 178, 179, with relative weights from 0.7550 to 1.5627 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B44.0?

Under the General Equivalence Mappings, invasive pulmonary aspergillosis converts to ICD-9-CM 117.3 (aspergillosis) and 484.6 (pneum in aspergillosis). 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.