ICD-10 · PDGM grouping
R18 Ascites
All 2 codes in the R18 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
2
Can lead a claim
0
Cannot lead a claim
2
What CMS assigns to R18
None of the 2 codes is assigned a clinical group. None of the 2 is assigned a comorbidity subgroup. None can lead a claim. CMS attaches a code-first note to 1 of the 2.
Code first
CMS grouper convention 153, on R18.0. Code first:
- malignancy, such as:
- malignant neoplasm of ovary (C56.-)
- secondary malignant neoplasm of retroperitoneum and peritoneum (C78.6)
Every code in R18
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| R18.0 | Malignant ascites | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | None |
| R18.8 | Other ascites | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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