R18.8 — Other ascites
R18.8 is a billable, specific ICD-10-CM code for other ascites. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Ascites NOS
- Peritoneal effusion (chronic)
Risk adjustment
R18.8 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
R18.8 is named in 7 Medicare coverage policies — 7 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56421Billing and Coding: CT of the Abdomen and Pelvis
- A56464Billing and Coding: Flow Cytometry
- A56697Billing and Coding: Non-Invasive Vascular Studies
- A56758Billing and Coding: Non-Invasive Vascular Studies
How R18.8 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to R18.8.
- Ascites(abdominal)
- Hydroperitoneum
- Ascites›pseudochylous
- Dropsy, dropsical›abdomen
- Effusion›peritoneal(chronic)
- Fluid›abdomen
- Fluid›peritoneal cavity
- Hydrops›abdominis
Related codes at this level
Codes that share R18. If R18.8 is not quite right, the correct code is usually one of these.
Questions about R18.8
- Is R18.8 a billable ICD-10-CM code?
- Yes. R18.8 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does R18.8 sit in the tabular list?
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), in the block Symptoms and signs involving the digestive system and abdomen (R10-R19).