I33.9 – Acute and subacute endocarditis, unspecified

ICD-10-CM 2027 diagnosis code · Other forms of heart disease

Billable code

ICD-10-CM code I33.9
Code
I33.9 (claims format: I339)
Description
Acute and subacute endocarditis, unspecified
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
9. Diseases of the circulatory system (I00-I99)
Block
I30-I5A Other forms of heart disease
Parent codes
I33

Notes for I33.9

Applicable to:
  • Acute endocarditis NOS
  • Acute myoendocarditis NOS
  • Acute periendocarditis NOS
  • Subacute endocarditis NOS
  • Subacute myoendocarditis NOS
  • Subacute periendocarditis NOS

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

I33 – Acute and subacute endocarditis

Excludes1 (not coded here):
  • acute rheumatic endocarditis (I01.1)
  • endocarditis NOS (I38)

Index terms for I33.9

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in I33

Frequently asked questions

What is ICD-10 code I33.9?

I33.9 is the ICD-10-CM code for acute and subacute endocarditis, unspecified, in the block I30-I5A (Other forms of heart disease).

Is I33.9 a billable code?

Yes. I33.9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does I33.9 belong to?

It belongs to category I33 – Acute and subacute endocarditis.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.