OBJECTIVES: Approximately 13.7 million hospital discharges in 2013 (~30% of all hospital discharges) involved treatment of infectious organisms. An estimated 1.14 MM patients are admitted to the hospital every year for treatment of pneumonia and over 20% of bacterial pneumonia cases are caused by drug resistant organisms. The objective of the present study was to examine the outcomes and costs associated with drug resistant pneumonia in a large sample of US patients. METHODS: This retrospective study examined prospectively collected data from a large, de-identified US electronic health record database covering >49M patient encounters from >600 participating facilities. We retrospectively analyzed encounters involving adults diagnosed with pneumonia during an emergency inpatient or outpatient admission between January 2010 and March 2015. RESULTS: The final study population included 103,502 patient visits. The most common bacterial species in pneumonia infections were Staphylococcus aureus (9%), Staphylococcus sp. Coag Negative (9%), and Escherichia coli (9%). Drug resistant infections resulted in higher median hospital costs per patient compared to drug susceptible infections ($16,171 vs. $11,451). Patients with drug resistant pneumonia were 26% more likely to experience acute kidney injury (drug resistant 24.6%; drug susceptible 19.5%). Length of stays (LOS) in the intensive care unit (ICU) and hospital were 26% and 33% higher, respectively for patients with drug resistant pneumonia (median ICU LOS 7.5 days vs. 6.0 days; median hospital LOS 11.9 days vs. 9.0 days). Additionally, patients with drug resistant pneumonia had higher mortality rates (3.40% vs. 0.81%). CONCLUSIONS: This analysis identified greater hospital costs, longer length of stays, and higher mortality rates in pneumonia patients with drug resistant bacterial species compared to patients with drug susceptible bacterial species. These findings provide insights into resource allocation for treatment of drug resistant infections and support the importance of developing treatment options to circumvent established antibiotic resistances.