R18 is a non-billable ICD-10-CM category code for ascites, so it cannot be submitted on claims. Use a more specific code from this category instead, such as R18.0 and R18.8. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established.
Code Identity
Code Classification
Specific Coding for AscitesOverview
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to R18: its own notes plus those printed at block R10-R19 and Chapter 18. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- fluid in peritoneal cavity
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- congenital or infantile pylorospasm (Q40.0)
- gastrointestinal hemorrhage (K92.0-K92.2)
- intestinal obstruction (K56.-)
- newborn gastrointestinal hemorrhage (P54.0-P54.3)
- newborn intestinal obstruction (P76.-)
- pylorospasm (K31.3)
- signs and symptoms involving the urinary system (R30-R39)
- symptoms referable to female genital organs (N94.-)
- symptoms referable to male genital organs (N48-N50)
Notes
General instructions on how these codes are used.
- This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
- Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
- The conditions and signs or symptoms included in categories R00-R94 consist of:
- (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
- (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
- (c) provisional diagnosis in a patient who failed to return for further investigation or care;
- (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
- (e) cases in which a more precise diagnosis was not available for any other reason;
- (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name R18, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming R18: they are not reported together with it, unless the two conditions are unrelated.
Clinical InformationClinical
Ascites
accumulation or retention of free fluid within the peritoneal cavity.
Patient EducationClinical
Liver Diseases
Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code HistoryHistory
Questions About R18Overview
What is the ICD-10 code for ascites?
R18 is the ICD-10-CM category for ascites, but it is a non-billable header: claims need a more specific code from this category, listed on this page.
Is R18 (Ascites) a billable code?
No. This is a category header that groups the codes for ascites, and headers cannot be submitted on claims. Claims for ascites need a more specific code from this category, such as R18.0 and R18.8.
Can R18 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the ascites is established, that condition takes the principal position instead.
Can R18 be reported with K70.31?
Not as a rule. The Excludes1 note on R18 lists "ascites in alcoholic cirrhosis (K70.31)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
