The transition from elementary to middle school is associated with increases in anxiety and related impairment, yet few evidence-based interventions exist to support students with impairing anxiety during this transition. This study describes the feasibility of a novel intervention, delivered by school mental health professionals (SMHPs), for students with impairing anxiety who are transitioning from elementary to middle school. The multi-component group intervention, referred to as TEAMSS (Transitioning Emotionally and Academically to Middle School Successfully), focuses on lowering anxiety and increasing academic organizational and social skills. TEAMSS was evaluated in two open trials over two academic school years with a total of 21 students (M age: 10.8 years old; 67% female; 76% Caucasian). Intervention feasibility, fidelity, and satisfaction ratings are presented. Preliminary pre-post student outcomes of anxiety and related impairment were collected from independent evaluators, parents, and students. Results indicated that the intervention was feasible to conduct in schools (100% of student group meetings were delivered), fidelity was fair, and satisfaction ratings were positive. Preliminary pre-post student outcomes revealed statistically significant reductions in student anxiety symptoms according to independent evaluators (but not child or parent report). Parents reported reducing maladaptive accommodation of anxiety; no improvements in academic organizational or social skills were observed. Lessons learned from this feasibility study are discussed. TEAMSS has the potential to fill a gap in the school-based intervention literature for students with anxiety transitioning to middle school but requires a randomized controlled trial to determine its efficacy.