Blastomycosis (B40) ICD-10-CM
The B40 code range covers blastomycosis with 10 ICD-10-CM diagnosis codes. 8 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the B40 Range 10 codes · 8 billable
- B40 BlastomycosisNon-billable
- B40.0 Acute pulmonary blastomycosis
- B40.1 Chronic pulmonary blastomycosis
- B40.2 Pulmonary blastomycosis, unspecified
- B40.3 Cutaneous blastomycosis
- B40.7 Disseminated blastomycosis
- B40.8 Other forms of blastomycosisNon-billable
- B40.81 Blastomycotic meningoencephalitis
- B40.89 Other forms of blastomycosis
- B40.9 Blastomycosis, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the B40 range.
Blastomyces
A genus of onygenacetous mitosporic fungi whose perfect state is Ajellomyces (see ONYGENALES). The species Blastomyces dermatitidis (perfect state is Ajellomyces dermatitidis) causes blastomycosis.
Blastomycosis
A fungal infection by BLASTOMYCES that may appear in two forms: 1, a primary lesion characterized by the formation of a small cutaneous nodule and small nodules along the lymphatics that may heal within several months; and 2, chronic granulomatous lesions characterized by thick crusts, warty growths, and unusual vascularity and infection in the middle or upper lobes of the lung.
Lobomycosis
A chronic, fungal, subcutaneous infection endemic in rural regions in South America and Central America. The causal organism is Lacazia labol.
Paracoccidioidomycosis
A mycosis affecting the skin, mucous membranes, lymph nodes, and internal organs. It is caused most often by Paracoccidioides brasiliensis. It is also called paracoccidioidal granuloma.
About the B40 Code Range
The ICD-10 code B40 and its subcodes classify different forms of blastomycosis, a fungal infection caused by the fungus Blastomyces dermatitidis. These codes are used to specify whether the infection affects the lungs, skin, or other organs, and whether it is acute, chronic, disseminated, or unspecified.
Healthcare professionals use codes like B40.0 for acute pulmonary blastomycosis, also called primary pulmonary blastomycosis, to document infections of the lungs with symptoms starting suddenly. For chronic lung infection, B40.1 is used. B40.3 covers cutaneous blastomycosis, which affects the skin, sometimes referred to as primary or disseminated cutaneous blastomycosis. The code B40.7 indicates disseminated blastomycosis, where the fungus spreads beyond the initial site. Other specialized forms, such as meningoencephalitis due to blastomycosis, are coded as B40.81. When the site of infection is unclear or involves other organs like the liver, heart, or eyes, B40.89 or B40.9 are applied. Using these ICD-10 codes for blastomycosis helps accurately record the specific fungal infection, guiding treatment and epidemiological tracking.
Questions About This Page
How many billable codes are in the B40 range?
Of the 10 codes in this range, 8 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the B40 range classify?
The range classifies blastomycosis. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
