Objective: The objective of this study was to describe practices of 2- and 4-year institutional partnerships effective in supporting transfer student success. Method: Using student records from the National Student Clearinghouse (NSC) for the entire 2007 fall cohort of first-time-in-college community college students nationwide, researchers identified partnerships of 2- and 4-year institutions that were more effective than expected (controlling for student and institutional characteristics) in enabling community college entrants to transfer to a 4-year institution and earn a bachelor's degree. Based on this methodology, and in partnership with the Aspen Institute's College Excellence Program, researchers visited six pairs of 2- and 4-year college transfer partnerships identified as high performers, interviewing more than 350 faculty, student-facing and senior-level staff, and transfer students. Results: From these in-depth interviews, researchers identified a set of essential transfer practices common among these highly effective institutional partnerships. The practices were grouped under three broad strategies: (a) make transfer a priority, (b) create clear programmatic pathways with aligned high-quality instruction, and (c) provide tailored transfer advising. Contributions: This study offers a set of essential transfer practices culled from national fieldwork to 2- and 4-year institutional transfer partnerships identified using NSC data as highly effective in supporting transfer student success.