This review includes programs meeting NIEER's definition of state-funded preschool programs: Programs must be funded, controlled and directed by the state and serve at least 1% of the state's 3- and/or 4-year-old population. The focus of the program must be primarily educational and offer group learning experiences at least two days per week. In 2016-2017, 59 programs operating in 43 states and D.C. met this definition. Since our 2016 Essential Elements scan, more programs were added, including California's Transitional Kindergarten, Connecticut's Smart Start, Minnesota's Voluntary Prekindergarten program, and Oregon's Preschool Promise. This analysis evaluated the extent to which each state-funded preschool program satisfied 15 "essential elements" found to characterize high-quality public preschool programs. For each element, we determined whether criteria were fully met, partially met, or not met. (author abstract)