To evaluate the effectiveness of Carolinas Healthcare Outpatient Antimicrobial Stewardship Empowerment Network (CHOSEN), a multicomponent outpatient stewardship program to reduce inappropriate antibiotic prescribing for upper respiratory infections by 20% over 2 years. Before-and-after interrupted time series of antibiotics prescribed between 2 periods: April 2016-October 2017 and May 2018-March 2020. The study included 162 primary-care practices within a large healthcare system in the greater Charlotte, North Carolina region. Adult and pediatric patients with encounters for upper respiratory infections for which an antibiotic is inappropriate. Patient and provider educational materials, along with a web-based provider prescribing dashboard aimed at reducing inappropriate antibiotic prescribing were developed and distributed. Monthly antibiotic prescribing rates were calculated as the number of eligible encounters with an antibiotic prescribed divided by the total number of eligible encounters. A segmented regression analysis compared monthly antibiotic prescribing rates before versus after CHOSEN implementation, while also accounting for practice type and seasonal trends in prescribing. Overall, 286,580 antibiotics were prescribed during 704,248 preintervention encounters and 277,177 during 832,200 intervention encounters. Significant reductions in inappropriate prescribing rates were observed in all outpatient specialties: family medicine (relative difference before and after the intervention, -20.4%), internal medicine (-19.5%), pediatric medicine (-17.2%), and urgent care (-16.6%). A robust multimodal intervention that combined a provider prescribing dashboard with a targeted education campaign demonstrated significant decreases in inappropriate outpatient antibiotic prescribing for upper respiratory tract infections in a large integrated ambulatory network.