This brief presents select findings from the "Conversion of Enrollment Slots from Head Start to Early Head Start (HS2EHS) Case Studies," six case studies of grant recipients that converted enrollment slots from Head Start to Early Head Start in 2021. This brief focuses on "developing the application to convert enrollment slots." The full report includes findings pertaining to the entire conversion process from start to finish. Specifically, this brief highlights findings related to the following research questions: (1) How do grant recipients prepare requests for conversion?; (2) What technical assistance, resources, or other supports are available and useful for grant recipients?; (3) What facilitates OHS Regional Office review and approval of requests for conversion?; (4) What data do grant recipients leverage when preparing a request for conversion?; (5) What facilitates successful preparation of a conversion application?; and (6) What are the barriers to preparing a conversion application?