R18 — Ascites
Is R18 billable?
No — R18 is a non-billable header code. R18 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 2 billable codes beneath R18.
Billable codes under this header
R18 at a glance
| Code | R18 |
|---|---|
| Description | Ascites |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with R18 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Includes
Conditions classified to R18.
- fluid in peritoneal cavity
Excludes2 — not included here — inherited from Chapter 18
The conditions below are not part of R18, but a patient may have both at the same time. When documentation supports it, R18 and the excluded code may both be reported.
Excludes2 — not included here — inherited from R10-R19
The conditions below are not part of R18, but a patient may have both at the same time. When documentation supports it, R18 and the excluded code may both 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)
What codes fall under R18? (2)
How long has R18 existed?
R18 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.