Behavior intervention plans (BIPs) are intended to help educators systematically support students with behavioral problems at school. Previous research confirms that the effectiveness of a BIP depends on the degree to which the plan is technically adequate and implemented with integrity. What remains unclear from the literature is how professional experience and environmental variables impact technical adequacy, treatment integrity, and student outcomes. The purpose of this study was to explore these relationships using data collected from a survey of members' experiences with the BIP implementation team. The researchers collected BIPs from local school districts and then surveyed members of the implementation team regarding their professional qualifications, training, involvement in the BIP development process, treatment integrity, and perceived impact on student outcomes. Results from two multiple regression models predicting treatment integrity and student outcomes suggest that practitioners' perceptions of BIP quality significantly predicted treatment integrity. Additionally, training, BIP quality, and treatment integrity significantly predicted student outcomes. These findings suggest that practitioners' perceptions of BIP quality may play an important role in predicting treatment integrity but improving student outcomes requires technical adequacy and targeted professional development.