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ICD-10-CM 2027

ICD-10 code for pharyngitis chlamydia

A56.4

Chlamydial infection of pharynx

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Chlamydia, chlamydial › pharyngitis”. Page updated September 29, 2026.

About coding pharyngitis chlamydia

The ICD-10-CM code for pharyngitis chlamydia is A56.4 (Chlamydial infection of pharynx).

Within A56 (other sexually transmitted chlamydial diseases), A56.4 is specifically for chlamydial infection of pharynx. Related codes cover chlamydial infection of lower genitourinary tract (A56.0), chlamydial infection of pelviperitoneum and other genitourinary organs (A56.1), chlamydial infection of genitourinary tract, unspecified (A56.2), chlamydial infection of anus and rectum (A56.3) and sexually transmitted chlamydial infection of other sites (A56.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 152 (Otitis Media and URI with MCC, relative weight 1.1151) and DRG 153 (Otitis Media and URI without MCC, relative weight 0.7421), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

Common questions about pharyngitis chlamydia ICD-10 codes

What is the ICD-10 code for pharyngitis chlamydia?

A56.4 — Chlamydial infection of pharynx.

Is A56.4 billable?

Yes. A56.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can A56.4 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict A56.4 as a principal diagnosis.

Is A56.4 a CC or MCC?

No. A56.4 is neither a CC nor an MCC under MS-DRG v44.0.