ICD-10 Code for Rectosigmoiditis
The ICD-10-CM code for rectosigmoiditis is K63.89 — Other specified diseases of intestine. This is the code the Alphabetic Index gives for rectosigmoiditis with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
K63.89 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which rectosigmoiditis code should you use?
The Alphabetic Index lists 8 codes under Rectosigmoiditis. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| ulcerative | K51.30 | Ulcerative (chronic) rectosigmoiditis without complications |
Rectosigmoiditis ulcerative
| with › complication | K51.319 | Ulcerative (chronic) rectosigmoiditis with unspecified complications | |
| with › complication › abscess | K51.314 | Ulcerative (chronic) rectosigmoiditis with abscess | |
| with › complication › fistula | K51.313 | Ulcerative (chronic) rectosigmoiditis with fistula | |
| with › complication › obstruction | K51.312 | Ulcerative (chronic) rectosigmoiditis with intestinal obstruction | |
| with › complication › rectal bleeding | K51.311 | Ulcerative (chronic) rectosigmoiditis with rectal bleeding | |
| with › complication › specified NEC | K51.318 | Ulcerative (chronic) rectosigmoiditis with other complication |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources