OBJECTIVES:  The objective of this study was to assess the prevalence of concomitant psychotropic use and its association with all cause-hospitalization among Medicare beneficiaries. METHODS:  In this longitudinal study, the Medicare Current Beneficiary Survey (MCBS) was used to identify beneficiaries who were psychotropic drug users between 2007 and 2012, >=65 years old, community dwelling and continuously enrolled in parts A, B and D for >= 2 consecutive years. Each year, beneficiaries were characterized as single users, short-term concomitant users (<=90 days overlap of 2+ drugs), or long-term concomitant users (>90 days overlap of 2+ drugs). Hospitalization for any cause was measured yearly. In this repeated measures design, we assessed psychotropic use in the year prior to hospitalizations to address temporality. Generalized estimating equations (GEE) in multivariable logit models were used to estimate the odds of hospitalizations adjusted for demographic covariates, smoking, reported health status, total activities of daily living, instrumental activities of daily living and number of chronic conditions. RESULTS: Of the 1,612 beneficiaries identified as psychotropic drug users, 64% were single users, 9% were short-term concomitant users and 28% were long term concomitant users at baseline. 24% were hospitalized during follow up. From 2007 to 2012, concomitant psychotropic use consistently ranged from 36% to 38%, with the exception of 2008, when concomitant use increased to 40%. Long-term concomitant use was more prevalent than short-term use, ranging from 27% to 31% vs. 6% to 9%. Short-term concomitant use decreased from 9% in 2007 to 7% in 2012. Compared to single users, short-term concomitant users and long-term users had 45% (95% CI: 1.07-1.95) and 30% (95% CI: 1.07-1.57) increased odds of hospitalization. CONCLUSIONS:  Among older Medicare beneficiaries, short and long-term concomitant psychotropic use is associated with all-cause hospitalizations. Providers should exercise caution when prescribing psychotropic drugs concomitantly in this patient population.