ICD-10-CM 2027 diagnosis code
R18.8Other ascites
R18.8 is a valid, billable ICD-10-CM code for other ascites. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Ascites, ICD-10 code for Hydroperitoneum.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About R18.8
R18.8 is the ICD-10-CM diagnosis code for other ascites. It belongs to category R18 (ascites), block R10-R19 (symptoms and signs involving the digestive system and abdomen) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within R18, choose R18.8 (Other ascites) only when documentation doesn't support a more specific option: malignant ascites (R18.0).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 947 (Signs and Symptoms with MCC, relative weight 1.261) and DRG 948 (Signs and Symptoms without MCC, relative weight 0.7835), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 568.82 (peritoneal effusion (chronic)) and 789.59 (other ascites).
Coding notes
- Ascites NOS
- Peritoneal effusion (chronic)
Notes that apply from higher levels
Instructions written at a parent level also apply to R18.8.
› From R18 Ascites
Broader instructions also apply from R10-R19 Symptoms and signs involving the digestive system and abdomen and Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.
Alphabetic index entries
8 entriesTerms in the official ICD-10-CM index that lead to R18.8.
Codes whose notes reference R18.8
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 23 · Factors Influencing Health Status and Other Contacts with Health Services
ICD-9-CM equivalent
Converter →From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about R18.8
Is R18.8 billable?
- Yes. R18.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R18.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R18.8 as a principal diagnosis.
Is R18.8 a CC or MCC?
- R18.8 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does R18.8 group to?
- R18.8 is used in the MS-DRG v44.0 logic for MS-DRG 947 (Signs and Symptoms with MCC) and MS-DRG 948 (Signs and Symptoms without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for R18.8?
- The CMS General Equivalence Mappings map R18.8 to ICD-9-CM 568.82 and 789.59.