When patients are discharged from the hospital, they (and their informal caregivers) are given copious amounts of information that must also be communicated to their primary care provider. This qualitative study of primary care and hospital physicians, nurses, and pharmacists highlights several barriers to complete and effective communication between levels of care, particularly regarding geriatric medication safety. Barriers include the large number of complex patients and incongruent expectations of responsibility of primary and hospital providers. Support systems, such as electronic health records, can both enable and hinder communication.