Is ICD-10-CM code K66.9 billable?

Yes, K66.9 (Disorder of peritoneum, unspecified) is a billable ICD-10-CM diagnosis code, valid for reimbursement on HIPAA-covered transactions for FY2027.

What chapter does ICD-10-CM code K66.9 belong to?

K66.9 belongs to Chapter 11 of the ICD-10-CM tabular list: K00–K95 (Diseases of the Digestive System).

K66.9BillableNon-CC No HCC

Disorder of peritoneum, unspecified

Diseases of the Digestive System·Other disorders of peritoneum·subcategory·FY 2027

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 more about peritoneal disorders on MedlinePlus · Source: MedlinePlus, National Library of Medicine

Also indexed as: Disease, peritoneum

Instructional notes

Also applies, from K66: Other disorders of peritoneum

These notes sit on K66 and apply to every code under it, including K66.9.

Excludes2: not included here, code separately if applicable

ascites (R18.-)
peritoneal effusion (chronic) (R18.8)

Where K66.9 sits

K65-K6A Diseases of peritoneum, retroperitoneum and pelvis (K65-K6A)
K66 Other disorders of peritoneum
K66.9 Disorder of peritoneum, unspecified

MS-DRGs

As the principal diagnosis, this code groups to these MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

ICD-9-CM equivalent

Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).

568.9 Unspecified disorder of peritoneum

ICD-9 to ICD-10 converter