A new report in the New England Journal of Medicine found that Medicaid expansion in Oregon actually increased use of the emergency room (ER) by people newly covered by Medicaid. Policy experts had expected ER use to fall as people gained coverage and could have a usual source of care, such as a primary care physician. Within the first 15 months after gaining coverage, ER use spiked by about 40%, and remained high for subsequent years. It did not appear the people using the emergency room were necessarily substituting ER visits for primary care physicians (PCP) visits. Rather, PCP visits and ER visits appeared to be complementary.
Mercatus senior research fellow Brian Blase covers the implications in much more detail at Forbes. Blase points out that the value of Medicaid benefits is less than the cost, enrollees are misusing their benefits (ER visits when primary care would suffice). ER overuse makes it harder for those truly in need of emergency care to be seen in a timely manner. It is also arguably why the cost of Medicaid expansion is far above initial projections.