B35 ICD-10-CM Code: Dermatophytosis

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for B35 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on B35 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for B35

MedCoder structured workflow — derived from this code’s own official record

Before you code B35

1. B35 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewB35.0, B35.1, B35.2, B35.3, B35.4, B35.5, B35.6, B35.8, B35.9

   See the relationships section · Guide: How to choose an ICD-10-CM code →

Choose the right path

1. Does the documentation support one of the more specific codes beneath B35?
   Yes → Select that code and continue the checks below on its own page.
   No → B35 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewB35.0, B35.1, B35.2, B35.3, B35.4, B35.5, B35.6, B35.8, B35.9

Consider B35. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Official instructions as workflow

• Excludes2 — not part of B35(2 notes)

  Coding workflow: The conditions named in this note are not included in B35. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareJ67, C84.0

  See the official tabular notes · Guidelines I.A.12.b

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse B35 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of B35 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• J67— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of hypersensitivity pneumonitis due to organic dust adds J67; it is not part of this code and both may be reported when both are documented.

  Full comparison: B35 vs J67 →

• C84.0— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of mycosis fungoides adds C84.0; it is not part of this code and both may be reported when both are documented.

  Full comparison: B35 vs C84.0 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• Not billable as written — a more specific code is required: B35.0, B35.1, B35.2, B35.3, B35.4.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name B35 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Code First instruction: M01 — Direct infections of joint in infectious and parasitic diseases classified elsewhere.

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Contextual Map

Every relationship of B35 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run B35 with these 3 related codes in Claim Check

Hierarchy

• A00-B99 — Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99) (A00-B99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35-B49 — Mycoses[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Excludes2

• C84.0 — Mycosis fungoides[Excludes2]: “mycosis fungoides (C84.0-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• J67 — Hypersensitivity pneumonitis due to organic dust[Excludes2]: “hypersensitivity pneumonitis due to organic dust (J67.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• M01 — Direct infections of joint in infectious and parasitic diseases classified elsewhere[Code First]: “mycoses (B35-B49)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Nearest codes (9)

• B35.0 — Tinea barbae and tinea capitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.1 — Tinea unguium[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.2 — Tinea manuum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.3 — Tinea pedis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.4 — Tinea corporis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.5 — Tinea imbricata[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.6 — Tinea cruris[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• B35.8 — Other dermatophytoses[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 1 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to B35 in its code family, with their registry titles.

• B35.0 — Tinea barbae and tinea capitis
• B35.1 — Tinea unguium
• B35.2 — Tinea manuum
• B35.3 — Tinea pedis
• B35.4 — Tinea corporis
• B35.5 — Tinea imbricata
• B35.6 — Tinea cruris
• B35.8 — Other dermatophytoses
• B35.9 — Dermatophytosis, unspecified