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A74

A74Other diseases caused by chlamydiae

Non-billable headerICD-10-CM

A74 is a non-billable header ICD-10-CM code for other diseases caused by chlamydiae. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • neonatal chlamydial conjunctivitis (P39.1)
  • neonatal chlamydial pneumonia (P23.1)
  • Reiter's disease (M02.3-)
  • sexually transmitted chlamydial diseases (A55-A56)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • chlamydial pneumonia (J16.0)

Other codes that can never be billed with A74

These codes carry an Excludes1 note pointing at A74. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A74 alone.

  • A49Bacterial infection of unspecified site
  • K65Peritonitis
  • K67Disorders of peritoneum in infectious diseases classified elsewhere

Risk adjustment

A74 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead A74

3 child codes. Green means billable.

Questions about A74

Is A74 a billable ICD-10-CM code?
No. A74 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A74 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Other diseases caused by chlamydiae (A70-A74).
What cannot be coded together with A74?
A74 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.