R18.0 - Malignant ascites

Version 2023
Billable Code
No Valid Principal Dx
Unacceptable Principal Diagnosis
MS-DRG Mapping
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ICD-10:R18.0
Short Description:Malignant ascites
Long Description:Malignant ascites
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00–R99)
    • Symptoms and signs involving the digestive system and abdomen (R10-R19)
      • Ascites (R18)

R18.0 is a billable ICD-10 code used to specify a medical diagnosis of malignant ascites. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

According to ICD-10-CM guidelines this code should not to be used as a principal diagnosis code when a related definitive diagnosis has been established.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Clinical Information

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to this diagnosis code:


Code First

Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

Index to Diseases and Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
R18.0789.51 - Malignant ascites

Patient Education


Liver Diseases

Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons.

There are many kinds of liver diseases:

Symptoms of liver disease can vary, but they often include swelling of the abdomen and legs, bruising easily, changes in the color of your stool and urine, and jaundice, or yellowing of the skin and eyes. Sometimes there are no symptoms. Tests such as imaging tests and liver function tests can check for liver damage and help to diagnose liver diseases.


[Learn More in MedlinePlus]

Code History

Previous Code: R18

Parent Code: R18

Next Code: R18.8