Background: Community-acquired pneumonia (CAP), urinary tract infection (UTI), pharyngitis, acute otitis media (AOM), and skin and soft-tissue infection (SSTI) are among the most common outpatient conditions for which antibiotics are prescribed. The objective of this study was to describe the observed duration of outpatient antibiotic therapy compared with guideline recommendations for these common conditions in 2017 in the United States to identify antibiotic stewardship targets. Methods: We estimated therapy duration for oral and parenteral antibiotic prescriptions associated with CAP, AOM, pharyngitis, acute cystitis, pyelonephritis, SSTI, and sinusitis diagnoses from the IQVIA National Disease and Therapeutic Index 2017 dataset, a two-stage stratified cluster sample of office-based physician visits. We excluded azithromycin due to its unique pharmacokinetics, and we limited our study to prescriptions from emergency medicine, family practice, general practice, geriatrics, internal medicine, osteopathic medicine, and pediatrics physicians. We excluded observations with antibiotic prescriptions for multiple conditions. We used NDTI projection weights and complex sample methods to estimate antibiotic prescription numbers and durations by condition and age group. Results: Table 1 shows antibiotic prescriptions by condition and population. The median antibiotic therapy duration for all conditions except acute cystitis was 10 days. The median duration for acute cystitis was 7 days. Conclusions:Clinicians prescribed 10-day antibiotic courses for the most common outpatient conditions, regardless of guideline-recommended duration. Antibiotic stewardship efforts targeting excessive durations of antibiotic therapy for common outpatient conditions, particularly sinusitis in adults, CAP, SSTI, and acute cystitis, are needed.Funding: This work was supported by the Centers for Disease Control and Prevention. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.Disclosures: Laura M. King is a contractor employed by Northrop Grumman Corporation to fulfill research needs at the Centers for Disease Control and Prevention as part of a contract covering many positions and tasks. All other authors declare no conflicts.