ICD-10 R18
Non-Billable HeaderAscites
About ICD-10-CM R18
ICD-10-CM code R18 represents Ascites. This is a non-billable header code in the Symptoms, Signs, and Abnormal Findings chapter (block R18). The 2026 edition of ICD-10-CM R18 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 1 Excludes
Pure excludes, these codes can never be coded together with R18. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- ascites in alcoholic cirrhosis (K70.31)
- ascites in alcoholic hepatitis (K70.11)
- ascites in toxic liver disease with chronic active hepatitis (K71.51)
Includes
- fluid in peritoneal cavity
Medicare LCD Coverage for R18
Local Coverage Determinations (LCDs) from CMS MACs that list R18 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing R18.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but R18 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with R18
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To R18
Other codes in section R10-R19 (Symptoms and signs involving the digestive system and abdomen).
ICD-10 R18, Billing FAQ
Is ICD-10 code R18 billable? +
No, R18 is a non-billable header code. Use a more specific child code from block R18 when submitting claims.
What codes are Type 1 Excludes for R18? +
Type 1 Excludes (never code together with R18): ascites in alcoholic cirrhosis (K70.31); ascites in alcoholic hepatitis (K70.11); ascites in toxic liver disease with chronic active hepatitis (K71.51)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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