This study describes and analyzes the benefits and costs of investing in a public, voluntary, high-quality universal prekindergarten program made available to all 3- and 4-year-olds across the United States. By breaking down these benefits and costs at the state and national levels, we show how such a program would strengthen the U.S. economy's competitiveness while simultaneously easing a host of fiscal, social, and health problems. Over time, the program would more than pay for itself: By 2050, a universal prekindergarten program would yield $8.90 in benefits for every dollar invested and $304.7 billion in total benefits. (author abstract)