This brief provides reflections from four Mathematica evaluation technical assistance (TA) liaisons based on their experiences in working with grantees awarded as part of a Federal interagency initiative, the Performance Partnership Pilots for Disconnected Youth (P3). In this brief, we (1) describe the P3 program’s TA supports, (2) review the roles and responsibilities of different types of P3 partners, and (3) describe the hurdles faced when working with partners and strategies to mitigate those hurdles. While this paper focuses on challenges, it should be noted that the partnerships of the grantees included strengths as well. Some of the mitigation strategies discussed were identified by reflecting on the differences between partnerships that did and did not encounter a specific hurdle.