ICD-10-CM category K65: Peritonitis

Notes that apply to every K65 code

Excludes1 (never coded together)

• acute appendicitis with generalized peritonitis (K35.2-)
• aseptic peritonitis (T81.6)
• benign paroxysmal peritonitis (E85.0)
• chemical peritonitis (T81.6)
• gonococcal peritonitis (A54.85)
• neonatal peritonitis (P78.0-P78.1)
• pelvic peritonitis, female (N73.3-N73.5)
• periodic familial peritonitis (E85.0)
• peritonitis due to talc or other foreign substance (T81.6)
• peritonitis in chlamydia (A74.81)
• peritonitis in diphtheria (A36.89)
• peritonitis in syphilis (late) (A52.74)
• peritonitis in tuberculosis (A18.31)
• peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
• peritonitis with or following appendicitis (K35.-)
• puerperal peritonitis (O85)
• retroperitoneal infections (K68.-)

Use additional code

• code (B95-B97), to identify infectious agent, if known

Code also

• if applicable diverticular disease of intestine (K57.-)

Billable codes in K65

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

• ICD-10-CM FY2027 tabular order file (category titles)
  Version FY2027 · effective 2026-10-01 · file icd10cm_order_2027.txtSHA-256 38981fb2c1226e2b…
• ICD-10-CM FY2027 tabular list (chapter titles and ranges)
  Version FY2027 · effective 2026-10-01 · file 2027-code-tables-tabular-index.zipSHA-256 37baa476323714be…
• ICD-10-CM FY2027 code descriptions addenda (codes added, deleted and revised)
  Version FY2027 · effective 2026-10-01 · file icd10cm_codes_addenda_2027.txtSHA-256 cfba025073235af4…
• ICD-10 MS-DRG Definitions Manual v44 (text)
  Version v44 · effective 2026-10-01 · file fy2027-fr-icd10-ms-drg-definitions-manual-files-v44.zipSHA-256 ae4f6c11727fe91f…
• IPPS FY2027 Tables 6A-6K: new, invalid and revised ICD-10-CM/PCS codes, CC/MCC list changes and CC exclusions
  Version FY2027 (final rule; not reissued by CN3) · effective 2026-10-01 · file fy2027-ipps-fr-tables-6a-6k.zipSHA-256 ca0af87b0869a405…
• ICD-10-CM FY2027 POA-exempt codes (full list, additions, deletions and revisions)
  Version FY2027 · effective 2026-10-01 · file 2027-poa-exempt-codes.zipSHA-256 03f55091045024d0…
• ICD-10-CM to CMS-HCC V28 mappings, payment year 2027 initial
  Version PY2027 initial ICD-10-CM mappings (dates of service 2026) · effective 2027-01-01 · file 2027 Initial ICD-10-CM Mappings.csvSHA-256 9c260b06d0dd2806…
• Medicare Coverage Database, current Billing and Coding Articles export
  Version MCD release 2026-10-08 · effective 2026-10-04 · file article.csvSHA-256 5e95c4a8ac3664be…