I22 Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction

The ICD-10-CM code for Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction is I22 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

9: Diseases of the circulatory system (I00-I99)

Section

I20-I25: Ischemic heart diseases (I20-I25)

Category I22

6 codes (5 billable)

FY2026 Status

Stable since FY2024

Official Coding Guidelines

Use of I22 for subsequent AMI within 4 weeks; with I21

4) Subsequent acute myocardial infarction A code from category I22, Subsequent ST elevation (STEMI) and non- ST elevation (NSTEMI) myocardial infarction, is to be used when a patient who has suffered a type 1 or unspecified AMI has a new AMI within the 4 week time frame of the initial AMI. A code from category I22 must be used in conjunction with a code from category I21. The sequencing of the I22 and I21 codes depends on the circumstances of the encounter.

Do not use I22 for subsequent MI other than type 1/unspecified

Do not assign code I22 for subsequent myocardial infarctions other than type 1 or unspecified. For subsequent type 2 AMI assign only code I21.A1. For subsequent type 4 or type 5 AMI, assign only code I21.A9.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool