ICD-10-CM 2027
ICD-10 code for proctosigmoiditis
From the official ICD-10-CM alphabetic index entry “Proctosigmoiditis”. Page updated September 29, 2026.
About coding proctosigmoiditis
The ICD-10-CM code for proctosigmoiditis is K63.89 (Other specified diseases of intestine).
Within K63.8, choose K63.89 (Other specified diseases of intestine) only when documentation doesn't support a more specific option: Dieulafoy lesion of intestine (K63.81) and intestinal microbial overgrowth (K63.82).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 393 (Other Digestive System Diagnoses with MCC, relative weight 1.5881), DRG 394 (Other Digestive System Diagnoses with CC, relative weight 0.9228) and DRG 395 (Other Digestive System Diagnoses without CC/MCC, relative weight 0.6382), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific proctosigmoiditis codes (official index)
- ulcerative (chronic)
Common questions about proctosigmoiditis ICD-10 codes
What is the ICD-10 code for proctosigmoiditis?
- K63.89 — Other specified diseases of intestine.
Is K63.89 billable?
- Yes. K63.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K63.89 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K63.89 as a principal diagnosis.
Is K63.89 a CC or MCC?
- No. K63.89 is neither a CC nor an MCC under MS-DRG v44.0.