K63.821Header code — not billable
Small intestinal bacterial overgrowth
- Chapter
- 11. Diseases of the digestive system
- Category
- K63
- Effective date
- October 1, 2026
Related codes in category K63
K63Other diseases of intestineK63.0Abscess of intestineYesK63.1Perforation of intestine (nontraumatic)YesK63.2Fistula of intestineYesK63.3Ulcer of intestineYesK63.4EnteroptosisYesK63.5Polyp of colonYesK63.8Other specified diseases of intestineK63.81Dieulafoy lesion of intestineYesK63.82Intestinal microbial overgrowthK63.8211Small intestinal bacterial overgrowth, hydrogen-subtypeYesK63.8212Small intestnl bact overgrowth, hydrogen sulfide-subtypeYes
Frequently asked questions
What is ICD-10 code K63.821?
K63.821 is an ICD-10-CM diagnosis code for Small intestinal bacterial overgrowth.
Is K63.821 a billable code?
No. K63.821 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is K63.821 in?
K63.821 falls under Chapter 11: Diseases of the digestive system.
When did K63.821 become effective?
K63.821 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to K63.821?
K63.821 belongs to category K63, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.