A74.81 — Chlamydial peritonitis
A74.81 is a billable, specific ICD-10-CM code for chlamydial peritonitis. It is valid for submission on a claim.
Excludes1 inherited from the categories above A74.81
These are not written on A74.81, but they bind it: a note on a category applies to every code beneath it. Billing A74.81 with anything listed here is a denial.
Excludes2 inherited from the categories above A74.81
Also inherited, and the opposite of Excludes1: these conditions are not part of A74.81, but a patient can have both, so you may code both.
Other codes that can never be billed with A74.81
These codes carry an Excludes1 note pointing at A74.81. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A74.81 alone.
Risk adjustment
A74.81 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.
How A74.81 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to A74.81.
- Chlamydia, chlamydial›peritonitis
- Peritonitis›chlamydial
- Fitzhugh-Curtis syndrome›due to›Chlamydia trachomatis
- Syndrome›Fitzhugh-Curtis›due to›Chlamydia trachomatis
Code history
A74.81 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share A74.8. If A74.81 is not quite right, the correct code is usually one of these.
Questions about A74.81
- Is A74.81 a billable ICD-10-CM code?
- Yes. A74.81 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does A74.81 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 A74.81?
- A74.81 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above A74.81 (A74) and apply to it just the same.