Objectives: To evaluate the impact of implementing an evidence-based fall prevention intervention in community senior centers., Methods: We used a single-group design to evaluate the Tai Ji Quan: Moving for Better Balance (TJQMBB) program's adoption, population reach, implementation, effectiveness, and maintenance among 36 senior centers in 4 Oregon counties between 2012 and 2016. The primary outcome measure, as part of the effectiveness evaluation, was number of falls as ascertained by self-report. Trained TJQMBB instructors delivered the program to community-dwelling older adults for 48 weeks, with a 6-month postintervention follow-up., Results: TJQMBB was adopted by 89% of the senior centers approached and reached 90% of the target population. The program resulted in a 49% reduction in the total number of falls and improved physical performance. Participation was well maintained after the program's completion. The average cost-effectiveness ratio for the 48-week program implementation was $917 per fall prevented and $676 per fall prevented for multiple falls., Conclusions: TJQMBB is an effective public health program that can be broadly implemented in community senior centers for primary prevention of falls among community-dwelling older adults.