ICD-10 Code A56.3 – Chlamydial infection of anus and rectum (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A56.3 – Chlamydial infection of anus and rectum
What it is
A56.3 identifies chlamydial infection involving the anus and rectum. Use it when documentation specifies rectal or anorectal chlamydia caused by Chlamydia trachomatis.
Clinical signs
Clinical features may include rectal pain, discharge, bleeding, or tenesmus. Some patients have no symptoms, so you should rely on documented diagnosis and exam or test results.
When to use this code
Use this code when the provider documents chlamydial proctitis, rectal chlamydia, or infection of the anus and rectum. It also fits confirmed anorectal infection even if symptoms are mild or absent. Check documentation if the site is not clearly stated.
Do not use for
Do not use A56.3 for non-chlamydial proctitis or for chlamydial infection at another site, such as the genitourinary tract. If documentation only says “chlamydia” without location, check documentation.
Coding tip
Code the anatomic site exactly as documented; anorectal involvement is not the same as genital chlamydia.