Eliminating inappropriate antibiotic use in pediatric lower respiratory tract infections (LRTI) is the central focus of this research. LRTIs (pneumonia, bronchiolitis, and infection-related exacerbations of asthma) account for nearly one-third of all emergency department (ED) visits and 40% of all infection-related hospitalizations in US children. LRTIs also account for more antibiotic use in children's hospitals than any other condition, despite most LRTIs being viral in nature. Inappropriate antibiotics are associated with substantial adverse effects. Accordingly, national guidelines strongly discourage routine antibiotic use for bronchiolitis and acute asthma and argue for significantly reducing antibiotic exposure (initiation, spectrum, and duration) in pneumonia. To address the problem of inappropriate antibiotic use, hospital-based antimicrobial stewardship programs (ASPs) are now common nationwide, and these programs have demonstrated effectiveness in some hospital settings. Unfortunately, traditional ASP approaches do not translate well to the fast-paced and unpredictable ED environment, and hospital-based ASP resources are finite and not always immediately available. Clinical decision support (CDS) embedded within the electronic health record (EHR) is a strategy that could address the ED antibiotic stewardship gap. Informed by a deep understanding of the key facilitators and barriers to using CDS to support appropriate antibiotic use in ED and hospital settings, the investigators have developed two stewardship-focused CDS interventions for pediatric LRTI. The overarching goal of this research is to rigorously evaluate the implementation and effectiveness of these CDS tools, alone and in combination, against usual care only in a pragmatic randomized clinical trial at 3 U.S. children's hospitals.