R18 Ascites

Category / Non-billable header 2 subcodes

Block: Symptoms and signs involving the digestive system and abdomen (R10-R19)

Includes

  • fluid in peritoneal cavity

Excludes 1 (cannot be coded together)

  • ascites in alcoholic cirrhosis (K70.31)
  • ascites in alcoholic hepatitis (K70.11)
  • ascites in toxic liver disease with chronic active hepatitis (K71.51)

Subcodes

Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.

Code Description Billable
R18..0 Malignant ascites Yes
R18..8 Other ascites Yes

Last reviewed: September 2026