2026 ICD-10-CM Diagnosis Code B40.2Pulmonary blastomycosis, unspecified
ICD-10-CM Codes›A00–B99›B35-B49›B40
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
B40.2 is a billable ICD-10-CM diagnosis code for pulmonary blastomycosis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 791, 793, 867 through 869. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 14 closely related codes. Coders also document this condition as infection by Blastomyces dermatitidis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections and Other specified and unspecified lower respiratory disease.
B40.2 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 115 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 115, ESRD (V21) category 115, and ESRD (V24) category 115 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
B40.2 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Infection by Blastomyces dermatitidis
- Pulmonary blastomycosis
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
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.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 caused by inhalation of spores of blastomyces dermatitidis. it presents with flu-like symptoms including fever, chills, cough, pleuritic chest pain and myalgias. it may lead to a chronic granulomatous pulmonary infection and disseminate to other anatomic sites including skin, nervous system and bones.North American Blastomycosis|Blastomyces Dermatitidis Infection
a pulmonary disease resulting from infection with blastomyces dermatitidis, which is prevalent in north america.
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 B40.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B40.2Overview
What is the ICD-10 code for pulmonary blastomycosis, unspecified?
The ICD-10-CM code for pulmonary blastomycosis, unspecified is B40.2 (sometimes written as B402). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is B40.2 (Blastomycosis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report pulmonary blastomycosis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does B40.2 group to?
When pulmonary blastomycosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, 867, 868, 869, with relative weights from 0.7297 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B40.2 a CC or MCC?
CMS lists B40.2 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 14 closely related codes in its exclusion list.
What is the ICD-9 equivalent of B40.2?
Under the General Equivalence Mappings, pulmonary blastomycosis, unspecified converts to ICD-9-CM 116.0 (blastomycosis). The mapping is approximate, so confirm the match fits the documentation.
Does B40.2 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. B40.2 mapped to HCC 115 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 115 (Pneumococcal Pneumonia/Empyema/Lung Abscess), ESRD (V21) category 115 (Pneumococcal Pneumonia/Empyema/Lung Abscess), and ESRD (V24) category 115 (Pneumococcal Pneumonia/Empyema/Lung Abscess).
