Our High-Performing Transfer Partnerships (HPTP) study uses quantitative data to find institutional pairs of community colleges and baccalaureate-granting institutions (BGI) within states that have better than average results on bachelor's completion and/or retention for all students and students of color. Once these pairs are identified, our research team visits the community colleges and baccalaureate-granting institutions to gather qualitative data to identify practices that may contribute to these positive student outcomes. Our analysis is continuing and already we are learning that pairs of institutions are shifting from seeing themselves as operating singularly and separately, in the ways they enroll and serve students, to seeing themselves as "sister" institutions that work toward a common goal of supporting their shared students to attain a baccalaureate degree. This brief summarizes promising practices that our data show support and maintain partnerships that have positive outcomes for students, including underserved student populations. (For more explanation of the High-Performing Transfer Partnership (HPTP) study, Yeh, 2018, Data Note 1 [see ED608148].) [For Data Note 3, see ED608151.]