Research supports the use of multi-tiered systems of support (MTSS) for meeting student academic, behavioral, and socioemotional needs. MTSS is viewed as an ideal model to deliver school-based mental health (SBMH) services to students. However, limited research has examined what this framework for service delivery looks like in practice. Utilizing a national participant sample and a mixed-methods convergent (quan + QUAL) design, the purpose of this study is to examine participant use of MTSS for SBMH and to examine practitioners' perspectives on the implementation of Tier 2 and 3 services. Respondents in our current sample indicated a level of uncertainty regarding the identification of students for SBMH services and the delivery of Tier 2 and Tier 3 services, particularly as this relates to special education. Additionally, respondents indicated "insufficient" supports for the provision of Tier 3 services. Limitations, implications for practice, and future directions are discussed.