Lipoprotein(a) Lp(a) is a well-recognized, independent risk factor for atherosclerotic cardiovascular disease, with elevated levels estimated to be prevalent in 20% of the population. Observational and genetic evidence strongly support a causal relationship between high plasma concentrations of Lp(a) and increased risk of atherosclerotic cardiovascular disease–related events, such as myocardial infarction and stroke, and valvular aortic stenosis. In this scientific statement, we review an array of evidence-based considerations for testing of Lp(a) in clinical practice and the utilization of Lp(a) levels to inform treatment strategies in primary and secondary prevention. •Causal association between high lipoprotein(a) Lp(a) and atherosclerotic cardiovascular disease–related events and mortality.•Laboratory methods and population-based considerations for Lp(a) cut points.•When to measure Lp(a) in adults and youth.•Treatment implications in primary and secondary prevention.