This study investigated outcome data obtained from six samples of primary school students, four of which consisted of at-risk students. Participants were: (1) 46 students from a transitional first-grade, developmental, regular education school readiness program (SRP) for at-risk kindergartners; (2) 20 nonplaced kindergartners who were recommended for SRP and who advanced directly into first grade; (3) 31 kindergartners judged ready for promotion into first grade from kindergarten; (4) 16 students held out of kindergarten; (5) 24 students retained in kindergarten, first, or second grade; and (6) a random sample of 18 second graders. Along with standardized achievement outcomes and demographic background variables, the investigation probed the role of teacher-rated social, problematic, behavioral, motivation, success, self-esteem, classroom participation, and engagement characteristics of students. Parent surveys examined the role of parental level of education, attitudes, and other contextual factors. Findings suggested that extra-year students were characterized by lower achievement ratings and teacher ratings than random or promoted students who were one year younger. Cautions about policy and a review of research on transitional first-grade program outcomes are appended. (RH)