BACKGROUND: With 30-day Medicare readmission rates reaching 20%, a heightened focus has been placed on improving the transition process from hospital to home. For many institutions, this charge has identified medication-use safety as an area where pharmacists are well-positioned to improve outcomes by reducing medication therapy problems (MTPs). METHODS: This system-wide (425 bed community hospital plus 18 primary care clinics) prospective study recruited inpatient and ambulatory pharmacists to provide comprehensive medication management before and after hospital discharge. The results analyzed were the success rate and timing of the inpatient to ambulatory pharmacist handoff, as well as the number, type, and severity of MTPs resolved in both settings. RESULTS: Of the 105 eligible patients who received a pharmacist evaluation before discharge, 61 (58%) received follow-up with an ambulatory pharmacist an average of 2.88 days after discharge (range 1-8 days). An average of 5 and 1.4 MTPs per patient were identified and resolved in the inpatient vs. ambulatory setting, respectively. Although average MTP severity ratings were higher in the inpatient setting, the highest severity rating was seen most frequently in the ambulatory setting. CONCLUSIONS: In the transition from hospital to home, pharmacist evaluation in both the inpatient and ambulatory settings are necessary to resolve medication therapy problems.