2026 ICD-10-CM Diagnosis Code A56Other sexually transmitted chlamydial diseases

ICD-10-CM CodesA00–B99A50-A64A56

ICD-10-CM A56
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A56 is a non-billable ICD-10-CM category code for other sexually transmitted chlamydial diseases, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A56.00, A56.01, A56.02, and A56.09.

Code Identity

ICD-10-CM Code
A56
Billable Status
No — Non-Billable Category
Code Describes
Other sexually transmitted chlamydial diseases
Chapter
A50-A64
Infections with a predominantly sexual mode of transmission

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA56Other sexually transmitted chlamydial diseases
This CodeA56Other sexually transmitted chlamydial diseases

Specific Coding for Other sexually transmitted chlamydial diseasesOverview

Non-specific codes like A56 require more characters. Use one of these billable codes instead:

  • A56.0 for Chlamydial infection of lower genitourinary tract

  • Use A56.00 for Chlamydial infection of lower genitourinary tract, unspecified

  • Use A56.01 for Chlamydial cystitis and urethritis

  • Use A56.02 for Chlamydial vulvovaginitis

  • Use A56.09 for Other chlamydial infection of lower genitourinary tract

  • A56.1 for Chlamydial infection of pelviperitoneum and other genitourinary organs

  • Use A56.11 for Chlamydial female pelvic inflammatory disease

  • Use A56.19 for Other chlamydial genitourinary infection

  • Use A56.2 for Chlamydial infection of genitourinary tract, unspecified

  • Use A56.3 for Chlamydial infection of anus and rectum

  • Use A56.4 for Chlamydial infection of pharynx

  • Use A56.8 for Sexually transmitted chlamydial infection of other sites

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • sexually transmitted diseases due to Chlamydia
  • trachomatis

Type 1 Excludes

  • neonatal chlamydial conjunctivitis P39.1
  • neonatal chlamydial pneumonia P23.1

Type 2 Excludes

  • chlamydial lymphogranuloma A55
  • conditions classified to A74

Patient EducationClinical

Chlamydia Infections

Chlamydia is a common sexually transmitted infection (STI). It is caused by bacteria called Chlamydia trachomatis. Anyone can get chlamydia. It often doesn't cause symptoms, so people may not know that they have it. Antibiotics can cure it. But if it's not treated, chlamydia can cause serious health problems.

The full article covers:

  • What is chlamydia?
  • How is chlamydia spread?
  • Who is more likely to get chlamydia?
  • What are the symptoms of chlamydia?
  • How is chlamydia diagnosed?
  • Who should be tested for chlamydia?
  • What other problems can chlamydia cause?
  • What are the treatments for chlamydia?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A56Overview

Is A56 (Other sexually transmitted chlamydial diseases) a billable code?

No. This is a category header that groups the codes for other sexually transmitted chlamydial diseases, and headers cannot be submitted on claims. Claims for other sexually transmitted chlamydial diseases need a more specific code from this category, such as A56.00, A56.01, and A56.02.