Although the number of schools implementing School-Wide Positive Behavioral Interventions and Supports (SWPBIS) is increasing, and there is great demand for evidence-based Tier 2 and 3 interventions for students requiring additional support, little systematic research has examined administrator support for such programming. This article examines staff- and school-level factors associated with staff members' perception of administrator support for SWPBIS and the implementation of Tier 2 and 3 interventions. Using data from 2,717 staff members in 45 elementary schools implementing SWPBIS, multilevel analyses were conducted. Results indicated that the schools' organizational health played an important role in staff members' perceptions of administrator support for SWPBIS and Tier 2 and 3 interventions, whereas the implementation quality of these interventions did not. Furthermore, perceived administrator support for Tier 2 and 3 interventions varied as a function of the staff members' role in the school. Implications for practice and future research are discussed. (Contains 2 tables.)