ICD-10-CM 2027
ICD-10 code for ulcerative chronic rectosigmoiditis
Ulcerative (chronic) rectosigmoiditis without complications
From the official ICD-10-CM alphabetic index entry “Rectosigmoiditis › ulcerative (chronic)”. Page updated September 29, 2026.
About coding ulcerative chronic rectosigmoiditis
The ICD-10-CM code for ulcerative chronic rectosigmoiditis is K51.30 (Ulcerative (chronic) rectosigmoiditis without complications). The official index lists 6 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on K51.30.
Within K51.3, choose K51.30 (without complications) only when documentation doesn't support a more specific option: with complications (K51.31).
Use an additional code to identify any associated fistulas, if applicable: anal fistula (K60.3-), anorectal fistula (K60.5-) and rectal fistula (K60.4-). Use an additional code to identify manifestations, such as: pyoderma gangrenosum (L88).
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.
More specific ulcerative chronic rectosigmoiditis codes (official index)
- with
- complication K51.319 — Ulcerative (chronic) rectosigmoiditis with unspecified complications
- abscess K51.314 — Ulcerative (chronic) rectosigmoiditis with abscess
- fistula K51.313 — Ulcerative (chronic) rectosigmoiditis with fistula
- obstruction K51.312 — Ulcerative (chronic) rectosigmoiditis with intestinal obstruction
- rectal bleeding K51.311 — Ulcerative (chronic) rectosigmoiditis with rectal bleeding
- specified NEC K51.318 — Ulcerative (chronic) rectosigmoiditis with other complication
Common questions about ulcerative chronic rectosigmoiditis ICD-10 codes
What is the ICD-10 code for ulcerative chronic rectosigmoiditis?
- K51.30 — Ulcerative (chronic) rectosigmoiditis without complications. More specific codes apply when the documentation supports them: K51.319, K51.314, K51.313, K51.312 and others below.
Is K51.30 billable?
- Yes. K51.30 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K51.30 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K51.30 as a principal diagnosis.
Is K51.30 a CC or MCC?
- K51.30 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.