When both physicians and pharmacists in Taiwan prescribed and dispensed drugs, many elderly people considered the two types of health care providers more or less synonymous (i.e., close substitutes). Two policies mandated in the 1990s changed this perception: National Health Insurance (NHI), which provides insurance coverage to all citizens, and a separation policy (SP) that forbids physicians from dispensing and pharmacists from prescribing drugs. The author finds that by providing an economic incentive to the previously uninsured elderly, NHI raised the probability that they would visit physicians, relative to their continuously insured counterparts. In particular, some previously uninsured elderly who once only visited pharmacists were more likely to also visit physicians after NHI was implemented. Following this, the SP made it more likely that all elderly patients would only visit physicians and buy drugs from on-site pharmacists hired by physicians—a result different than its policy goal.