2027 ICD-10-CM Diagnosis Code K66Other disorders of peritoneum

ICD-10-CM Codes›K00–K95›K65-K6A›K66

ICD-10-CM K66
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

K66 is a non-billable ICD-10-CM category code for other disorders of peritoneum, so it cannot be submitted on claims. Use a more specific code from this category instead, such as K66.0, K66.1, K66.8, and K66.9.

Code Identity

ICD-10-CM Code
K66
Billable Status
No — Non-Billable Category
Code Describes
Other disorders of peritoneum
Short Description
Other disorders of peritoneum
Same as the full description in the CMS dataset.
Chapter
K65-K6A
Diseases of peritoneum and retroperitoneum

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK65-K6ADiseases of peritoneum and retroperitoneum
CategoryK66Other disorders of peritoneum
This CodeK66Other disorders of peritoneum

Specific Coding for Other disorders of peritoneumOverview

Non-specific codes like K66 require more characters. Use one of these billable codes instead:

  • Use K66.0 for Peritoneal adhesions (postprocedural) (postinfection)

  • Use K66.1 for Hemoperitoneum

  • Use K66.8 for Other specified disorders of peritoneum

  • Use K66.9 for Disorder of peritoneum, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to K66: its own notes plus those printed at Chapter 11. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On K66 itself
  • ascites (R18.-)
  • peritoneal effusion (chronic) (R18.8)
From Chapter 11 (K00-K95) Diseases of the digestive system applies to 863 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Patient EducationClinical

Peritoneal Disorders

Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About K66Overview

What is the ICD-10 code for other disorders of peritoneum?

K66 is the ICD-10-CM category for other disorders of peritoneum, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is K66 (Other disorders of peritoneum) a billable code?

No. This is a category header that groups the codes for other disorders of peritoneum, and headers cannot be submitted on claims. Claims for other disorders of peritoneum need a more specific code from this category, such as K66.0, K66.1, and K66.8.