R18
Non-billableAscites
Ascites
This is a header/category code. For billing purposes, use a more specific child code from the list below.
Coding Notes
Includes
Conditions included under this code
- fluid in peritoneal cavity
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
- •abnormal findings on antenatal screening of motherO28
- •certain conditions originating in the perinatal periodP04-P96
- signs and symptoms classified in the body system chapters
- •signs and symptoms of breast,N63, N64.5
- •congenital or infantile pylorospasmQ40.0
- •gastrointestinal hemorrhageK92.0-K92.2
- •intestinal obstructionK56
- •newborn gastrointestinal hemorrhageP54.0-P54.3
- •newborn intestinal obstructionP76
- •pylorospasmK31.3
- •signs and symptoms involving the urinary systemR30-R39
- •symptoms referable to female genital organsN94
- •symptoms referable to male genital organsN48-N50
Child Codes (2)
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(17)
UMLS
- Accumulation of fluid in the abdomenC0003962
- AscitesC0003962
- Ascites (disorder)C0003962
- Ascites NOSC0003962
- HydroperitoneumC0003962
- HydroperitoniaC0003962
- Hydrops abdominisC0003962
- abdominal dropsyC0003962
- ascitesC0003962
- hydroperitoneumC0003962
- hydroperitoniaC0003962
- hydrops abdominisC0003962
- peritoneal dropsyC0003962
- peritoneal exudateC0003962
- Fluid in peritoneal cavityC3665480
- Fluid in peritoneal cavity (finding)C3665480
- fluid in peritoneal cavityC3665480
Frequently Asked Questions
What is the ICD-10 code for ascites?
The ICD-10-CM code for ascites is R18. The full clinical description is "Ascites". R18 is a non-billable header code. Use a more specific child code for billing purposes.
What does ICD-10 code R18 mean?
ICD-10-CM code R18 represents “Ascites”. It is classified under Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings and is a non-billable header code. Use a more specific child code for billing purposes.
Is R18 a billable code?
No, R18 is a non-billable header code. You need to use one of its more specific child codes for billing. There are 2 child codes under R18.
What chapter is R18 in?
R18 is in Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings (codes R00-R99).
What codes cannot be used with R18?
R18 has Excludes1 notes indicating codes that cannot be used together with it, including: ascites in alcoholic cirrhosis (K70.31); ascites in alcoholic hepatitis (K70.11); ascites in toxic liver disease with chronic active hepatitis (K71.51).
What are the subcategories under R18?
R18 has 2 child codes, including: R18.0 (Malignant ascites), R18.8 (Other ascites).
What are the UMLS CUIs for R18?
R18 is linked to 2 UMLS Concept Unique Identifiers: C0003962, C3665480. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does R18 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like ascites affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of R18?
R18 maps to the ICD-11 code: ME04.Z (Ascites, unspecified).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.