2026 ICD-10-CM Diagnosis Code B45.0Pulmonary cryptococcosis

ICD-10-CM Codes›A00–B99›B35-B49›B45

ICD-10-CM B45.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B45.0 is a billable ICD-10-CM diagnosis code for pulmonary cryptococcosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869, 974 through 976. 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
B45.0
Billable Status
Yes — Valid for Submission
Code Describes
Pulmonary cryptococcosis
Short Description
Pulmonary cryptococcosis
Same as the full description in the CMS dataset.
Parent Code
B45
Cryptococcosis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB35-B49Mycoses
CategoryB45Cryptococcosis
This CodeB45.0Pulmonary cryptococcosis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pulmonary cryptococcosis

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.

    • Cryptococcosis, cryptococcus(infection) (neoformans)
      • pulmonary

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

  • Cryptococcosis

    fungal infection caused by genus cryptococcus.

  • Meningitis, Cryptococcal

    meningeal inflammation produced by cryptococcus neoformans, an encapsulated yeast that tends to infect individuals with acquired immunodeficiency syndrome and other immunocompromised states. the organism enters the body through the respiratory tract, but symptomatic infections are usually limited to the lungs and nervous system. the organism may also produce parenchymal brain lesions (torulomas). clinically, the course is subacute and may feature headache; nausea; photophobia; focal neurologic deficits; seizures; cranial neuropathies; and hydrocephalus. (from adams et al., principles of neurology, 6th ed, pp721-2)

  • Cryptococcus

    a mitosporic tremellales fungal genus whose species usually have a capsule and do not form pseudomycellium. teleomorphs include filobasidiella and fidobasidium.

  • AIDS-Related Cryptococcosis

    cryptococcosis associated with aids.

  • Cryptococcosis

    an acute or chronic, localized or disseminated infection by cryptococcus neoformans. sites of involvement include the lungs, central nervous system and meninges, skin, and visceral organs.--2004

Patient EducationClinical

Fungal Infections

If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful.

Read the full article at MedlinePlus

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

Convert B45.0 to ICD-9-CMHistory

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

ICD-9-CM
117.5 Cryptococcosis
Approximate The match is approximate rather than exact.

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 B45.0Overview

Is B45.0 (Cryptococcosis) a billable code?

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

What MS-DRG does B45.0 group to?

When pulmonary cryptococcosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, 974, 975, 976, with relative weights from 0.7297 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B45.0?

Under the General Equivalence Mappings, pulmonary cryptococcosis converts to ICD-9-CM 117.5 (cryptococcosis). 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.