Primary care providers are increasingly providing youth concussion care but report insufficient time and training, limiting adoption of best practices. We implemented a primary care–based intervention including an electronic health record–based clinical decision support tool (“SmartSet”) and in-person training. We evaluated consequent improvement in 2 key concussion management practices: (1) performance of a vestibular oculomotor examination and (2) discussion of return-to-learn/return-to-play (RTL/RTP) guidelines. Data were included from 7284 primary care patients aged 0 to 17 years with initial concussion visits between July 2010 and June 2014. We compared proportions of visits pre- and post-intervention in which the examination was performed or RTL/RTP guidelines provided. Examinations and RTL/RTP were documented for 1.8% and 19.0% of visits pre-intervention, respectively, compared with 71.1% and 72.9% post-intervention. A total of 95% of post-intervention examinations were documented within the SmartSet. An electronic clinical decision support tool, plus in-person training, may be key to changing primary care provider behavior around concussion care.