K66.9 Disorder of peritoneum, unspecified

Billable ICD-10-CM code, FY2026.

Applies from K66 Other disorders of peritoneum

Excludes2 (not included here)

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

MS-DRG index

Defines the logic of DRG(s) 393-395 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 568.9 Unspecified disorder of peritoneum

Diagnosis Index entries for K66.9

• Disease, diseased › peritoneum

Nearby codes

• K66 Other disorders of peritoneum
• K66.0 Peritoneal adhesions (postprocedural) (postinfection)
• K66.1 Hemoperitoneum
• K66.8 Other specified disorders of peritoneum
• K66.9 Disorder of peritoneum, unspecified (this code)