A54.85
BillableGonococcal peritonitis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A54.85 an HCC code?
Yes. A54.85 maps to Intestinal Obstruction/Perforation under the CMS-HCC V28 risk adjustment model (and Intestinal Obstruction/Perforation under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for A54.85
For A54.85 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed A54.85 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
A54.85 is the ICD-10-CM diagnosis code for gonococcal peritonitis. This is an infection of the peritoneum (the thin membrane lining the abdominal cavity) caused by the bacterium Neisseria gonorrhoeae, which is sexually transmitted. The infection causes inflammation and pain in the abdominal area. A54.85 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).
Under the CMS-HCC V28 risk adjustment model, A54.85 maps to Intestinal Obstruction/Perforation (HCC 78) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, A54.85 mapped to the same category but with a base RAF weight of 0.226 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify that the peritonitis is specifically documented as gonococcal in origin; do not use this code for peritonitis from other causes. Because A54.85 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A54.85 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify that the peritonitis is specifically documented as gonococcal in origin; do not use this code for peritonitis from other causes
- •Consider whether this is part of disseminated gonococcal infection (DGI) and check for additional codes for other affected sites such as joints or heart
Clinical Significance
Gonococcal peritonitis is a serious abdominal infection from disseminated gonorrhea, more commonly seen in females where pelvic infection can extend to the peritoneum. This represents a surgical emergency that requires prompt diagnosis and treatment to prevent sepsis and multi-organ failure.
Documentation Requirements
- ✓Confirmed Neisseria gonorrhoeae from peritoneal fluid culture or PCR
- ✓Imaging or surgical findings showing peritoneal inflammation
- ✓Clinical presentation: abdominal pain, guarding, rebound tenderness, fever
- ✓Route of spread documented (ascending pelvic infection, hematogenous dissemination)
- ✓Surgical intervention records if applicable (laparoscopy, laparotomy)
Excludes 1 — Do NOT code together
- gonococcal pelviperitonitis (A54.24)