ICD-10 K65
Non-Billable HeaderPeritonitis
About ICD-10-CM K65
ICD-10-CM code K65 represents Peritonitis. This is a non-billable header code in the Digestive System chapter (block K65). The 2026 edition of ICD-10-CM K65 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 1 Excludes
Pure excludes, these codes can never be coded together with K65. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- 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
When coding K65, also report these additional codes when applicable.
- code (B95-B97), to identify infectious agent, if known
Coding Notes
Code Also
- if applicable diverticular disease of intestine (K57.-)
Medicare LCD Coverage for K65
Local Coverage Determinations (LCDs) from CMS MACs that list K65 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing K65.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but K65 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with K65
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To K65
Other codes in section K65-K68 (Diseases of peritoneum and retroperitoneum).
ICD-10 K65, Billing FAQ
Is ICD-10 code K65 billable? +
No, K65 is a non-billable header code. Use a more specific child code from block K65 when submitting claims.
What codes are Type 1 Excludes for K65? +
Type 1 Excludes (never code together with K65): acute appendicitis with generalized peritonitis (K35.2-); aseptic peritonitis (T81.6); benign paroxysmal peritonitis (E85.0)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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