Out-of-school time programs are well-positioned to enhance students' Science, Technology, Engineering, and Math (STEM) skills, increase their interest in STEM fields, and increase their engagement in learning overall. In its 2011 Request for Proposals (RFP) for Out-of-School Time (OST) programs for youth in the elementary and middle grades, the New York City Department of Youth and Community Development (DYCD) encouraged programs to incorporate STEM subjects into their activities. In addition, DYCD's RFP required OST programs to institute a system of continuous quality improvement (CQI), which includes an examination of the program's goals and intended participant outcomes, observations and data collection, and adjustments to program practices based on this information. As part of its ongoing efforts to evaluate the implementation and effectiveness of the OST initiative, DYCD asked Policy Studies Associates, Inc. (PSA) to examine the ways in which OST programs implemented STEM activities, and to document their approaches to continuous quality improvement. This report describes the strategies and approaches used by five OST programs to implement STEM activities. Three of these programs were center-based and two were school-based; two of the programs served participants in grades K-5, one served grades 6-8, and two served both elementary- and middle-grades participants. This report is based on interviews with staff of these programs, as well as activity observations and document reviews. The first section of the report looks across the programs to examine the rationale for STEM implementation, and highlights areas where further technical assistance or guidance could strengthen implementation. The second section of the report contains a profile of each of the five programs visited for this study. [This report was prepared for Department of Youth and Community Development, New York, New York.]