R18.0
Billable codeMalignant ascites
The ICD-10 code for malignant ascites is R18.0.
Clinical notes
Code first
This code represents a manifestation of an underlying disease. Coding convention requires the underlying (etiology) code to be sequenced first, with this code listed second.
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This code represents a manifestation. Documentation should identify the underlying condition, which must be coded first.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- R18.8Other ascites
- R18.0Malignant ascites
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 78951
Associated MS-DRGs
R18.0 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.