A50-A64 ICD-10-CM Code: Infections with a predominantly sexual mode of transmission

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A50-A64 in the official ICD-10-CM tabular list, quoted as published.

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

Don’t confuse A50-A64 with…

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

The codes most likely to be picked instead of A50-A64 — 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.

• N34.1— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of nonspecific and nongonococcal urethritis moves the case to N34.1; the two are not reported together unless documented as unrelated.

  Full comparison: A50-A64 vs N34.1 →

• M02.3— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of Reiter's disease moves the case to M02.3; the two are not reported together unless documented as unrelated.

  Full comparison: A50-A64 vs M02.3 →

• B20— 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 human immunodeficiency virus [HIV] disease adds B20; it is not part of this code and both may be reported when both are documented.

  Full comparison: A50-A64 vs B20 →

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.

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

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 A50-A64 in its code family, with their registry titles.

• A50 — Congenital syphilis
• A51 — Early syphilis
• A52 — Late syphilis
• A53 — Other and unspecified syphilis
• A54 — Gonococcal infection
• A55 — Chlamydial lymphogranuloma (venereum)
• A56 — Other sexually transmitted chlamydial diseases
• A57 — Chancroid
• A58 — Granuloma inguinale
• A59 — Trichomoniasis
• A60 — Anogenital herpesviral [herpes simplex] infections
• A63 — Other predominantly sexually transmitted diseases, not elsewhere classified
• A64 — Unspecified sexually transmitted disease