ICD-10 Code I50.23 – Acute on chronic systolic (congestive) heart failure (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I50.23 – Acute on chronic systolic (congestive) heart failure
What it is
This code identifies a sudden worsening of chronic systolic heart failure, where the left ventricle does not pump effectively and congestion is present. Use it when the record clearly states acute on chronic systolic heart failure.
Clinical signs
Common findings include worsening dyspnea, fatigue, edema, orthopnea, and other signs of fluid overload. Clinical features vary; refer to documentation for whether the episode is acute, chronic, or both.
When to use this code
Use I50.23 when the provider documents an acute exacerbation or decompensation of known chronic systolic heart failure. It also fits notes that specify acute on chronic systolic CHF or similar wording. Check documentation if the record only says heart failure without the systolic component.
Do not use for
Do not use this code for isolated chronic systolic heart failure without an acute episode, or for heart failure type not documented as systolic. Check documentation if the note describes unspecified or diastolic heart failure.
Coding tip
Code the highest level of specificity documented, and query if the record does not clearly state both acute and chronic systolic heart failure.