ICD-10 Code B39 – Histoplasmosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B39 – Histoplasmosis
What it is
B39 identifies histoplasmosis, a fungal infection caused by Histoplasma species. It most often affects the lungs, but it can also spread beyond the respiratory system.
Clinical signs
Clinical features vary; refer to documentation. Common findings include cough, fever, chest discomfort, fatigue, and evidence of pulmonary or disseminated fungal infection.
When to use this code
Use B39 when the provider documents histoplasmosis without a more specific site or manifestation. It also applies when the record confirms histoplasma infection but does not specify acute, chronic, or disseminated form. Code to the highest documented specificity when available.
Do not use for
Do not use B39 for suspected histoplasmosis without confirmation if the record does not support a diagnosis. Do not substitute it for other fungal infections or for unrelated pulmonary conditions.
Coding tip
Check the note for the exact histoplasmosis type and anatomic site before assigning B39.