A56.4 – Chlamydial infection of pharynx

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

Billable code

ICD-10-CM code A56.4

Code: A56.4 (claims format: A564)
Description: Chlamydial infection of pharynx
Billable: Yes – valid for HIPAA-covered transactions
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
Parent codes: A56

Notes inherited from parent codes

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

A56 – Other sexually transmitted chlamydial diseases

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.-

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)

Index terms for A56.4

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in A56

Frequently asked questions

What is ICD-10 code A56.4?

A56.4 is the ICD-10-CM code for chlamydial infection of pharynx, in the block A50-A64 (Infections with a predominantly sexual mode of transmission).

Is A56.4 a billable code?

Yes. A56.4 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does A56.4 belong to?

It belongs to category A56 – Other sexually transmitted chlamydial diseases.

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.