ICD-10-CM B40 is the diagnosis code for Blastomycosis. This code falls under the section "Mycoses" within Chapter 1 — Certain infectious and parasitic diseases (A00-B99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as B40. They are mutually exclusive:
Understanding where B40 sits in the ICD-10-CM classification helps ensure proper coding:
No, B40 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
B40 is the ICD-10-CM diagnosis code for "Blastomycosis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
B40 is located in Section B35-B49 — "Mycoses" within Chapter 1 of the ICD-10-CM Tabular List.
B40 has 7 sub-code(s) that provide more specific detail: B40.0, B40.1, B40.2, B40.3, B40.7 and more.
Use B40 when the patients documented diagnosis matches "Blastomycosis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Blastomycosis is B40.
No, B40 is non-billable. Use a more specific sub-code for primary diagnosis billing.
B40 is in Chapter 1 of the ICD-10-CM Tabular List.
Type 1 Excludes for B40 include: Brazilian blastomycosis (B41.-); keloidal blastomycosis (B48.0).
Yes, B40 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.