A positive family history for bipolar disorder (BD) is presently the strongest predictor for BD. Over the last 2 decades, several longitudinal studies among children of patients with BD (bipolar offspring) identified converging evidence for early BD manifestations and associated parental and environmental risk factors.1 Risk for BD is elevated in bipolar offspring, but affected families want to know an individual risk estimate. Moreover, clinicians and policy makers want to know how to identify those youth at ultra high risk because this information may affect treatment and monitoring strategies. In this issue of JAMA Psychiatry, Hafeman and colleagues2 present a risk calculator for bipolar spectrum disorder (BPSD) in youth at familial risk for BD. Their work is an important step forward in the BD research field and potentially for clinical practice. Risk calculators are novel in psychiatry3 but are well-known instruments in general medicine (eg, the Framingham Risk Score is a widely used tool to assess risk for cardiovascular diseases). By entering specific risk variables, risk calculators may guide clinicians to weigh individual risk for disease and aid clinical decision making (eg, starting early intervention and frequent monitoring). The study by Hafeman and colleagues2 is the first to date to investigate the use of a risk calculator in youth at familial risk for BD.