I99Header code — not billable

Other and unspecified disorders of circulatory system

Chapter
9. Diseases of the circulatory system
Category
I99
Effective date
October 1, 2026

Related codes in category I99

I99.8Other disorder of circulatory systemYesI99.9Unspecified disorder of circulatory systemYes

Frequently asked questions

What is ICD-10 code I99?

I99 is an ICD-10-CM diagnosis code for Other and unspecified disorders of circulatory system.

Is I99 a billable code?

No. I99 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 I99 in?

I99 falls under Chapter 9: Diseases of the circulatory system.

When did I99 become effective?

I99 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to I99?

I99 belongs to category I99, 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.