2027 ICD-10-CM Diagnosis Code K66.8Other specified disorders of peritoneum
ICD-10-CM Codes›K00–K95›K65-K6A›K66
- Billable — Valid for Submission
- Not Chronic
K66.8 is a billable ICD-10-CM diagnosis code for other specified disorders of peritoneum. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 393 through 395. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified gastrointestinal disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Congenital mesocolic hernia
- Fibrosis of mesentery
- Fibrosis of pelvic cavity
- Hydrocele of canal of Nuck
- Intraperitoneal fibrosis
- Male frozen pelvis
- Male pelvic adhesions
- Malignant frozen pelvis
- Mesenteric cyst
- Mesenteric hernia
- Mesenteric pseudocyst
- Non-malignant frozen pelvis
- Non-malignant male frozen pelvis
- Omental cyst
- Omental hematoma
- Omental hemorrhage
- Omental pseudocyst
- Omental wrapping around peritoneal dialysis catheter
- Perirenal pseudocyst
- Peritoneal cyst
- Peritoneal fibrosis
- Peritoneal granuloma
- Peritoneal mouse
- Peritoneal pseudocyst
- Pneumoperitoneum
- Poor drainage of peritoneal dialysis catheter
- Structural abnormality of mesentery
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to K66.8: its own notes plus those printed at K66 and 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.
- 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.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Cyst (colloid) (mucous) (simple) (retention)
mesentery, mesenteric K66.8
omentum (lesser) K66.8
peritoneum K66.8
Disease, diseased See Also: Syndrome;
specified NEC K66.8
abdomen K66.8
peritoneum K66.8
peritonei K66.8
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
Convert K66.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K66.8Overview
What is the ICD-10 code for other specified disorders of peritoneum?
The ICD-10-CM code for other specified disorders of peritoneum is K66.8 (sometimes written as K668). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is K66.8 (Other disorders of peritoneum) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other specified disorders of peritoneum on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does K66.8 group to?
When other specified disorders of peritoneum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 394, 395, 393, with relative weights from 0.6379 to 1.5877 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of K66.8?
Under the General Equivalence Mappings, other specified disorders of peritoneum converts to ICD-9-CM 568.89 (peritoneal disorder NEC). The mapping is approximate, so confirm the match fits the documentation.
