The New York City Department of Youth and Community Development (DYCD) launched its Out-of-School Time (OST) Programs for Youth in September 2005. Together, DYCD and the city’s nonprofit community, working closely with the New York City Department of Education, extended services to more than 51,000 youth across the city in the initiative’s first year and is currently serving more than 80,000, making OST almost certainly the nation’s largest afterschool program effort. This report presents interim findings from the OST high school program, including data on program implementation and findings on participant engagement in OST programs and associated academic and social development outcomes.