K65
Non-Billable

Peritonitis

Non-Billable / Non-Specific Code

What is Peritonitis?

ICD-10-CM K65 is the diagnosis code for Peritonitis. This code falls under the section "Diseases of peritoneum and retroperitoneum" within Chapter 11 — Diseases of the digestive system (K00-K95). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

⛔ Excludes1

Coding Guidelines for K65

⛔ Type 1 Excludes (Never code together)

The following conditions should never be coded at the same time as K65. They are mutually exclusive:

  • 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.-)

ICD-10-CM Code Hierarchy

Understanding where K65 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 7 entries
K65.0Generalized (acute) peritonitisBillableK65.1Peritoneal abscessBillableK65.2Spontaneous bacterial peritonitisBillableK65.3CholeperitonitisBillableK65.4Sclerosing mesenteritisBillableK65.8Other peritonitisBillableK65.9Peritonitis, unspecifiedBillable
Related Codes

Frequently Asked Questions

Is K65 a billable ICD-10-CM code?

No, K65 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does K65 mean?

K65 is the ICD-10-CM diagnosis code for "Peritonitis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What section is K65 in?

K65 is located in Section K65-K68 — "Diseases of peritoneum and retroperitoneum" within Chapter 11 of the ICD-10-CM Tabular List.

What are the sub-codes of K65?

K65 has 7 sub-code(s) that provide more specific detail: K65.0, K65.1, K65.2, K65.3, K65.4 and more.

When should I use K65?

Use K65 when the patients documented diagnosis matches "Peritonitis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Peritonitis?

The ICD-10-CM code for Peritonitis is K65.

Can K65 be used for primary diagnosis?

No, K65 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is K65 in?

K65 is in Chapter 11 of the ICD-10-CM Tabular List.

What conditions are excluded from K65?

Type 1 Excludes for K65 include: acute appendicitis with generalized peritonitis (K35.2-); aseptic peritonitis (T81.6); benign paroxysmal peritonitis (E85.0) and more.

Is K65 valid for 2026?

Yes, K65 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousK64.9Unspecified hemorrhoidsNext →K65.0Generalized (acute) peritonitis
Code Details
K65
Peritonitis
Non-Billable / Non-Specific Code
11 — Diseases of the digestive system (K00-K95)
K65-K68 — Diseases of peritoneum and retroperitoneum
2026 ICD-10-CM