A54.85 ICD-10-CM Code: Gonococcal peritonitis

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A54.85 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on A54.85 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for A54.85

MedCoder structured workflow — derived from this code’s own official record

Before you code A54.85

1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with A54.85. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support a condition named in A54.85’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewA54.24, N34.1, M02.3

Consider A54.85. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Official instructions as workflow

• Excludes1 — check before selecting A54.85(3 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with A54.85: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareA54.24, N34.1, M02.3

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of A54.85(1 note)

  Coding workflow: The conditions named in this note are not included in A54.85. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareB20

  See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (3)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Fitzhugh-Curtis syndrome, due to, Neisseria gonorrhea (gonococcal peritonitis)
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion), gonococcal
• Syndrome, Fitzhugh-Curtis, due to, Neisseria gonorrhea (gonococcal peritonitis)

Don’t confuse A54.85 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of A54.85 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• A54.24— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of gonococcal pelviperitonitis moves the case to A54.24; the two are not reported together unless documented as unrelated.

  Full comparison: A54.85 vs A54.24 →

• N34.1— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of nonspecific and nongonococcal urethritis moves the case to N34.1; the two are not reported together unless documented as unrelated.

  Full comparison: A54.85 vs N34.1 →

• M02.3— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of Reiter's disease moves the case to M02.3; the two are not reported together unless documented as unrelated.

  Full comparison: A54.85 vs M02.3 →

• B20— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of human immunodeficiency virus [HIV] disease adds B20; it is not part of this code and both may be reported when both are documented.

  Full comparison: A54.85 vs B20 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name A54.85 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 3 Excludes1 notes across 2 chapters: A54.24 — Gonococcal female pelvic inflammatory disease, K65 — Peritonitis, K67 — Disorders of peritoneum in infectious diseases classified elsewhere.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 7 Excludes2 notes across 2 chapters: N34 — Urethritis and urethral syndrome (via A54.-), P35 — Congenital viral diseases (via A54.-), P35-P39 — Infections specific to the perinatal period (P35-P39) (via A54.-), P36 — Bacterial sepsis of newborn (via A54.-), P37 — Other congenital infectious and parasitic diseases (via A54.-), P38 — Omphalitis of newborn (via A54.-), P39 — Other infections specific to the perinatal period (via A54.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 191 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 371 (MDC 06), DRG 372 (MDC 06), DRG 373 (MDC 06).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INF010 — Sexually transmitted infections (excluding HIV and hepatitis) (default); DIG016 — Peritonitis and intra-abdominal abscess.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

A54.41 — Gonococcal spondylopathy, A54.42 — Gonococcal arthritis, A54.43 — Gonococcal osteomyelitis, A54.49 — Gonococcal infection of other musculoskeletal tissue, A54.5 — Gonococcal pharyngitis, A54.6 — Gonococcal infection of anus and rectum, A54.81 — Gonococcal meningitis, A54.82 — Gonococcal brain abscess, A54.83 — Gonococcal heart infection, A54.84 — Gonococcal pneumonia, A54.89 — Other gonococcal infections, A54.9 — Gonococcal infection, unspecified, A55 — Chlamydial lymphogranuloma (venereum), A56.00 — Chlamydial infection of lower genitourinary tract, unspecified, A56.01 — Chlamydial cystitis and urethritis, A56.02 — Chlamydial vulvovaginitis, A56.09 — Other chlamydial infection of lower genitourinary tract, A56.11 — Chlamydial female pelvic inflammatory disease, A56.19 — Other chlamydial genitourinary infection, A56.2 — Chlamydial infection of genitourinary tract, unspecified, +170 more

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Intestinal Obstruction/Perforation) for risk-adjusted payment.

K25.1 — Acute gastric ulcer with perforation, K25.2 — Acute gastric ulcer with both hemorrhage and perforation, K25.5 — Chronic or unspecified gastric ulcer with perforation, K25.6 — Chronic or unspecified gastric ulcer with both hemorrhage and perforation, K26.1 — Acute duodenal ulcer with perforation, K26.2 — Acute duodenal ulcer with both hemorrhage and perforation, K26.5 — Chronic or unspecified duodenal ulcer with perforation, K26.6 — Chronic or unspecified duodenal ulcer with both hemorrhage and perforation, K27.1 — Acute peptic ulcer, site unspecified, with perforation, K27.2 — Acute peptic ulcer, site unspecified, with both hemorrhage and perforation, K27.5 — Chronic or unspecified peptic ulcer, site unspecified, with perforation, K27.6 — Chronic or unspecified peptic ulcer, site unspecified, with both hemorrhage and perforation, K28.1 — Acute gastrojejunal ulcer with perforation, K28.2 — Acute gastrojejunal ulcer with both hemorrhage and perforation, K28.5 — Chronic or unspecified gastrojejunal ulcer with perforation, K28.6 — Chronic or unspecified gastrojejunal ulcer with both hemorrhage and perforation, K50.012 — Crohn's disease of small intestine with intestinal obstruction, K50.112 — Crohn's disease of large intestine with intestinal obstruction, K50.812 — Crohn's disease of both small and large intestine with intestinal obstruction, K50.912 — Crohn's disease, unspecified, with intestinal obstruction, +55 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Intestine Transplant Status/Complications

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Sexually transmitted infections (excluding HIV and hepatitis), Peritonitis and intra-abdominal abscess).

A54.41 — Gonococcal spondylopathy, A54.42 — Gonococcal arthritis, A54.43 — Gonococcal osteomyelitis, A54.49 — Gonococcal infection of other musculoskeletal tissue, A54.5 — Gonococcal pharyngitis, A54.6 — Gonococcal infection of anus and rectum, A54.81 — Gonococcal meningitis, A54.82 — Gonococcal brain abscess, A54.83 — Gonococcal heart infection, A54.84 — Gonococcal pneumonia, A54.86 — Gonococcal sepsis, A54.89 — Other gonococcal infections, A54.9 — Gonococcal infection, unspecified, A55 — Chlamydial lymphogranuloma (venereum), A56.00 — Chlamydial infection of lower genitourinary tract, unspecified, A56.01 — Chlamydial cystitis and urethritis, A56.02 — Chlamydial vulvovaginitis, A56.09 — Other chlamydial infection of lower genitourinary tract, A56.11 — Chlamydial female pelvic inflammatory disease, A56.19 — Other chlamydial genitourinary infection, +191 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Peritonitis”; these codes share that main term but sit in a different category of the Tabular List.

A18.31 — Tuberculous peritonitis (tuberculous), A36.89 — Other diphtheritic complications (diphtheritic), A50.08 — Early visceral congenital syphilis (syphilitic, congenital), A52.74 — Syphilis of liver and other viscera (syphilitic), A74.81 — Chlamydial peritonitis (chlamydial), E85.0 — Non-neuropathic heredofamilial amyloidosis (periodic, familial), K35.209 — Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation (with or following, appendicitis, generalized), K35.30 — Acute appendicitis with localized peritonitis, without perforation or gangrene (with or following, appendicitis, localized), K35.32 — Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess (with or following, appendicitis, with perforation or rupture), K57.00 — Diverticulitis of small intestine with perforation and abscess without bleeding (with or following, diverticular disease, small intestine), K57.01 — Diverticulitis of small intestine with perforation and abscess with bleeding (with or following, diverticular disease, small intestine, with, bleeding), K57.20 — Diverticulitis of large intestine with perforation and abscess without bleeding (with or following, diverticular disease, large intestine), K57.21 — Diverticulitis of large intestine with perforation and abscess with bleeding (with or following, diverticular disease, large intestine, with, bleeding), K57.40 — Diverticulitis of both small and large intestine with perforation and abscess without bleeding (with or following, diverticular disease, large intestine, with, small intestine), K57.41 — Diverticulitis of both small and large intestine with perforation and abscess with bleeding (with or following, diverticular disease, large intestine, with, small intestine, with bleeding), K57.80 — Diverticulitis of intestine, part unspecified, with perforation and abscess without bleeding (with or following, diverticular disease), K57.81 — Diverticulitis of intestine, part unspecified, with perforation and abscess with bleeding (with or following, diverticular disease, with bleeding), K65.0 — Generalized (acute) peritonitis (acute), K65.1 — Peritoneal abscess (with or following, abscess), K65.2 — Spontaneous bacterial peritonitis (spontaneous bacterial), +13 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HIV Screening Test

Contextual Map

Every relationship of A54.85 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run A54.85 with these 10 related codes in Claim Check

Hierarchy

• A00-B99 — Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99) (A00-B99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Excludes1

• A54.24 — Gonococcal female pelvic inflammatory disease[Excludes1]: “gonococcal pelviperitonitis (A54.24)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes1 notes

• A54.24 — Gonococcal female pelvic inflammatory disease[Excludes1]: “gonococcal peritonitis (A54.85)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K65 — Peritonitis[Excludes1]: “gonococcal peritonitis (A54.85)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K67 — Disorders of peritoneum in infectious diseases classified elsewhere[Excludes1]: “peritonitis in gonococcal (A54.85)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

• N34 — Urethritis and urethral syndrome[Excludes2](via A54.-): “urethritis in diseases with a predominantly sexual mode of transmission (A50-A64)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P35 — Congenital viral diseases[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P35-P39 — Infections specific to the perinatal period (P35-P39)[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P36 — Bacterial sepsis of newborn[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P37 — Other congenital infectious and parasitic diseases[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P38 — Omphalitis of newborn[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• P39 — Other infections specific to the perinatal period[Excludes2](via A54.-): “congenital gonococcal infection (A54.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• INF010 — Sexually transmitted infections (excluding HIV and hepatitis)[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• DIG016 — Peritonitis and intra-abdominal abscess[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

• HCC 78 — Intestinal Obstruction/Perforation [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 371 — MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITH MCC[MS-DRG]: “MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITH MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 372 — MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITH CC[MS-DRG]: “MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITH CC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 373 — MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITHOUT CC/MCC[MS-DRG]: “MAJOR GASTROINTESTINAL DISORDERS AND PERITONEAL INFECTIONS WITHOUT CC/MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 06 — Diseases and Disorders of the Digestive System[MDC crossing]: “Diseases and Disorders of the Digestive System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 5,744 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Fitzhugh-Curtis syndrome, due to, Neisseria gonorrhea (gonococcal peritonitis)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion), gonococcal[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Syndrome, Fitzhugh-Curtis, due to, Neisseria gonorrhea (gonococcal peritonitis)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (36)

• A54 — Gonococcal infection[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.0 — Gonococcal infection of lower genitourinary tract without periurethral or accessory gland abscess[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.00 — Gonococcal infection of lower genitourinary tract, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.01 — Gonococcal cystitis and urethritis, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.02 — Gonococcal vulvovaginitis, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.03 — Gonococcal cervicitis, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.09 — Other gonococcal infection of lower genitourinary tract[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A54.1 — Gonococcal infection of lower genitourinary tract with periurethral and accessory gland abscess[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 28 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Risk adjustment Official source data

2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to A54.85 in its code family, with their registry titles.

• A54.5 — Gonococcal pharyngitis
• A54.6 — Gonococcal infection of anus and rectum
• A54.8 — Other gonococcal infections
• A54.81 — Gonococcal meningitis
• A54.82 — Gonococcal brain abscess
• A54.83 — Gonococcal heart infection
• A54.84 — Gonococcal pneumonia
• A54.86 — Gonococcal sepsis
• A54.89 — Other gonococcal infections
• A54.9 — Gonococcal infection, unspecified

View all codes in the A54 family