Mycoses (B35-B49) ICD-10-CM
The B35–B49 section covers mycoses with 125 ICD-10-CM diagnosis codes, of which 104 are billable in fiscal year 2026. The section is organized into the 15 code ranges listed below.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Code Ranges in This Section 15 ranges · 125 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About the B35–B49 Code Range
ICD-10 codes B35-B49 cover a broad range of fungal infections known as mycoses, including superficial, systemic, and unspecified fungal diseases. This chapter includes detailed codes for common and rare fungal infections affecting the skin, nails, respiratory system, central nervous system, and other organs.
The range begins with B35, addressing various dermatophytoses such as tinea capitis (scalp ringworm), tinea corporis (body ringworm), tinea pedis (athlete’s foot), and tinea cruris (jock itch). Synonyms like "Tinea barbae" or "Onychomycosis" guide coders to precise diagnoses for hair, nail, and skin fungal infections. Superficial mycoses in B36 include conditions like pityriasis versicolor and tinea nigra, while B37 focuses on candidiasis, encompassing mucosal infections such as candidal stomatitis, vaginal candidiasis, and systemic candidiasis including candidal sepsis and meningitis. Codes B38 to B49 represent deep and systemic mycoses like coccidioidomycosis, histoplasmosis, blastomycosis, and aspergillosis, among others. These codes also cover rarer fungal diseases such as cryptococcosis, mucormycosis, and sporotrichosis with categories specifying pulmonary, cutaneous, disseminated, and meningitis forms, aiding in accurate documentation for diverse fungal infections.
Medical coders can rely on this chapter to differentiate fungal conditions by site and severity, using synonyms listed (for instance, "Pityriasis versicolor" under B36.0 or "Blastomycosis, unspecified" under B40.9) to clarify ambiguous terms. Healthcare providers find this range valuable for tracking infections from common athlete’s foot and candidiasis to life-threatening systemic mycoses. Accurate coding ensures appropriate diagnosis classification for treatment planning and reporting.
Questions About This Page
How many codes are in the B35-B49 range?
The B35-B49 range contains 125 ICD-10-CM diagnosis codes in FY 2026. 104 of them are billable, and the rest are category headers that organize the section.
What conditions does B35-B49 cover?
The range covers mycoses. The code ranges listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
