OBJECTIVES: The study aimed to examine the utilization patterns of Proton Pump Inhibitors (PPIs) among the elderly and the trends in PPI prescribing across physician specialties in US office-based settings. The study also evaluated various patient and physician-level factors affecting non-indication based PPI prescription in the above population. METHODS: This retrospective cross-sectional study used 2002-2010 National Ambulatory Medical Care Survey (NAMCS) and outpatient portion of the National Hospital Ambulatory Medical Care Survey (NHAMCS) data to evaluate PPI utilization patterns based on patient visits. PPI prescribing trend among different physician specialties was estimated using 2005-2010 NAMCS data. Evidence-based indications for PPIs included the US Food and Drug Administration (FDA) approved indications and the National Institute of Clinical Excellence (NICE) guidelines. Multivariable logistic regression was performed to examine the association between non-indication based PPI use and various patient and physician-level characteristics using 2008-2010 NAMCS data. RESULTS: The use of PPIs increased from 5.29% patient visits in 2002 to 11.82% in 2010 (p<.0001). Prescription of PPI without an appropriate indication by primary care physicians (54.26% to 48.84%), medical specialists (35.21% to 35.62%) and surgeons (10.52% to 15.53%) did not change significantly  between 2005-2010 (p=0.55). Additionally, 80.12% of patient visits involved PPI prescriptions without an appropriate indication. Results of multivariable logistic regression revealed that, patients with more than 3 chronic conditions were significantly more likely  to be prescribed a PPI without an appropriate indication as compared to patient visits without a chronic condition (Odds Ratio (OR) = 2.49, 95% Confidence Interval (CI): 1.26-4.94). CONCLUSIONS: PPI use among the elderly increased significantly over the study period, with 8 out of 10 patient visits involving PPI prescriptions without an appropriate indication. Additionally, the study found no change in PPI prescribing trend across physician specialties. These findings suggest the need to improve quality of PPI prescribing in the vulnerable elderly population.