ICD-10 Code A74.81 – Chlamydial peritonitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A74.81 – Chlamydial peritonitis
What it is
A74.81 identifies peritonitis caused by Chlamydia infection. Use it when the medical record documents inflammation of the peritoneum linked to chlamydial disease.
Clinical signs
Clinical features vary; refer to documentation. Typical notes may describe abdominal pain, tenderness, or signs of pelvic or intra-abdominal infection when chlamydia is identified as the cause.
When to use this code
Use this code when the provider clearly documents chlamydial peritonitis or peritoneal inflammation attributed to Chlamydia. It is appropriate when the diagnosis is confirmed or stated as the reason for evaluation or treatment. Check documentation if the infection site is unclear.
Do not use for
Do not use it for nonspecific peritonitis, pelvic inflammatory disease without peritoneal involvement, or chlamydial infection at another site. If the record does not link peritonitis to Chlamydia, check documentation.
Coding tip
Code the condition only when the causal relationship to Chlamydia is documented, not implied.