Over the last two decades, Iowa has increased public support for preschool programs through Shared Visions, Early Childhood Iowa, Part B (special education) preschool and the Statewide Voluntary Preschool Program (SVPP). SVPP was initiated in 2007-8 and designed to phase in universal coverage over four years. Most of those 2007-8 preschool participants were in third grade--the grade when Iowa Test of Basic Skills scores are reported to the state--in the 2011-12 school year. Included in student records and ITBS scores reported to the Iowa Department of Education is parental reporting on whether the child participated in preschool, as well as the child's race and free and reduced-price lunch (FRL), English-language learner (ELL) and special education status. This brief analyzes the relationship between reported preschool participation and third-grade reading proficiency. Parental reports do not distinguish the specific type of preschool program in which the child participated, but they do allow for comparisons of third-grade proficiency rates by reported preschool participation and by other child and family factors. (author abstract)