HFrEF ICD-10 Code: I50.21
Last updated: January 4, 2026
HFrEF (heart failure with reduced ejection fraction), also called systolic heart failure, is coded using I50.2x codes in ICD-10-CM.
HFrEF Code Selection
| Code | Description | Use When |
|---|---|---|
| I50.21 | Acute systolic heart failure | New onset or acute decompensation |
| I50.22 | Chronic systolic heart failure | Stable chronic HFrEF |
| I50.23 | Acute on chronic systolic heart failure | Chronic HFrEF with acute worsening |
Key Terminology Mapping
| Clinical Term | ICD-10 Code |
|---|---|
| HFrEF | I50.2x (systolic codes) |
| Systolic heart failure | I50.2x |
| Heart failure with reduced EF | I50.2x |
| EF <40% with heart failure | I50.2x |
| Dilated cardiomyopathy with HF | I50.2x + I42.0 |
Documentation Requirements
- EF percentage (typically <40% for HFrEF)
- Acuity: acute, chronic, or acute on chronic
- Underlying etiology: ischemic, idiopathic, etc.
- NYHA functional class if documented
Coding Tips
- Systolic = HFrEF: Use I50.2x for reduced EF
- Ischemic cardiomyopathy: Code I25.5 + I50.2x
- Nonischemic cardiomyopathy: Code I42.0 + I50.2x
- Query if EF 40-50%: This is HFmrEF (mid-range), usually coded as I50.2x
Related Codes
- I50.31-I50.33 - HFpEF (diastolic/preserved EF)
- I50.41-I50.43 - Combined systolic and diastolic
- I25.5 - Ischemic cardiomyopathy
- I42.0 - Dilated cardiomyopathy
Frequently Asked Questions
HFrEF (heart failure with reduced ejection fraction) uses ICD-10 codes I50.21 (acute), I50.22 (chronic), or I50.23 (acute on chronic). These are the systolic heart failure codes.
Code both I25.5 (Ischemic cardiomyopathy) and the appropriate I50.2x code for the heart failure. I25.5 captures the etiology while I50.2x captures the heart failure.
HFrEF is typically EF <40% (use I50.2x). HFpEF is typically EF >50% (use I50.3x). EF 40-50% is HFmrEF, often coded as I50.2x but may vary by payer.
Related Resources
Last updated: January 2026. Code data reflects ICD-10-CM 2026 version. This guide is for educational purposes only. Always verify codes against current official guidelines.