The American College of Cardiology (ACC) and the American Heart Association (AHA) staging classification of HF is a useful tool for categorizing patients across populations.
The staging system emphasizes the onset and progression of the disease, unlike the New York Heart Association functional classification system, which emphasizes exercise capacity in adults, adapted for patients < 6 years (Ross).

The International Society for Heart and Lung Transplantation (ISHLT) published guidelines and recommendations for the evaluation and treatment of HF in children in 2004 and proposed a staging classification  into four stages (Stages A–D), which is useful to identify those at risk for HF and who are currently asymptomatic (Stage A) versus those on the other end of the spectrum (Stage D), who have advanced HF and, thus, would require therapeutic interventions for maintenance of end-organ function.

Conolly et al in 2011 published the New York University (NYU) Pediatric HF Index. HF severity in NYU index is determined from signs and symptoms, medical regimen, and ventricular physiology (+2 points in single ventricle physiology). Scores can range from zero (no heart failure) to 30 (severe heart failure).