ICD-10 Code B40.8 – Other forms of blastomycosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B40.8 – Other forms of blastomycosis
What it is
B40.8 identifies blastomycosis cases that do not fit the more specific coded forms. Use it for confirmed Blastomyces infection when the documentation describes another presentation or site.
Clinical signs
Clinical features vary; refer to documentation. Blastomycosis may involve pulmonary, cutaneous, or disseminated disease, and diagnosis is usually supported by clinical findings plus microbiology or pathology.
When to use this code
Use B40.8 when the record confirms blastomycosis but does not specify the site or subtype needed for a more exact code. It also fits cases documented as an atypical or other form of blastomycosis. If the provider names a different blastomycosis category, code that more specific option instead.
Do not use for
Do not use this code for suspected blastomycosis without confirmation. Do not use it when documentation clearly supports a more specific blastomycosis code or another fungal infection.
Coding tip
Code the most specific blastomycosis diagnosis documented, and query the provider if the record only says “blastomycosis” without enough detail.