I33Header code — not billable
Acute and subacute endocarditis
- Chapter
- 9. Diseases of the circulatory system
- Category
- I33
- Effective date
- October 1, 2026
Related codes in category I33
Frequently asked questions
What is ICD-10 code I33?
I33 is an ICD-10-CM diagnosis code for Acute and subacute endocarditis.
Is I33 a billable code?
No. I33 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 I33 in?
I33 falls under Chapter 9: Diseases of the circulatory system.
When did I33 become effective?
I33 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to I33?
I33 belongs to category I33, which includes 2 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.