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Compare/A56 vs P23.1

A56 vs P23.1

A56 (Other sexually transmitted chlamydial diseases) compared with P23.1 (Congenital pneumonia due to Chlamydia), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. A56 carries an Excludes1 note covering P23.1: “neonatal chlamydial pneumonia (P23.1)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

A56Other sexually transmitted chlamydial diseasesP23.1Congenital pneumonia due to Chlamydia
Billing statusNon-billable header

Report instead: A56.00, A56.01, A56.02, A56.09, A56.11

Billable
ClassificationA00-B99 — Certain Infectious and Parasitic Diseases (A00-B99)P00-P96 — Certain Conditions Originating in the Perinatal Period (P00-P96)
DefinitionOther sexually transmitted chlamydial diseases is a non-billable ICD-10-CM category code (A56).Congenital pneumonia due to Chlamydia is a billable ICD-10-CM diagnosis code (P23.1).
Includes
sexually transmitted diseases due to Chlamydia
trachomatis
infective pneumonia acquired in utero or during birth

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources