A56 – Other sexually transmitted chlamydial diseases

ICD-10-CM 2027 diagnosis code · Infections with a predominantly sexual mode of transmission

Non-billable header

ICD-10-CM code A56

Code: A56 (claims format: A56)
Description: Other sexually transmitted chlamydial diseases
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 1. Certain infectious and parasitic diseases (A00-B99)
Block: A50-A64 Infections with a predominantly sexual mode of transmission

Billable codes under A56

A56 is a header code and cannot be used on claims. Choose the most specific code:

A56.0 – Chlamydial infection of lower genitourinary tractHeader (more codes below)
A56.1 – Chlamydial infection of pelviperitoneum and other genitourinary organsHeader (more codes below)
A56.2 – Chlamydial infection of genitourinary tract, unspecifiedBillable
A56.3 – Chlamydial infection of anus and rectumBillable
A56.4 – Chlamydial infection of pharynxBillable
A56.8 – Sexually transmitted chlamydial infection of other sitesBillable

Notes for A56

Includes:

sexually transmitted diseases due to Chlamydia
trachomatis

Excludes1 (not coded here):

neonatal chlamydial conjunctivitis (P39.1)
neonatal chlamydial pneumonia (P23.1)

Excludes2 (not included here):

chlamydial lymphogranuloma (A55)
conditions classified to A74.-

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block A50-A64

Excludes1 (not coded here):

nonspecific and nongonococcal urethritis (N34.1)
Reiter's disease (M02.3-)

Excludes2 (not included here):

human immunodeficiency virus [HIV] disease (B20)

Frequently asked questions

What is ICD-10 code A56?

A56 is the ICD-10-CM code for other sexually transmitted chlamydial diseases, in the block A50-A64 (Infections with a predominantly sexual mode of transmission).

Is A56 a billable code?

No. A56 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.