Per Visit Emergency Department Expenditures By Insurance Type, 1996-2015.

Between 1996 and 2015, mean annual increases in per visit emergency department (ED) expenditures were significantly greater for private insurance than Medicare, Medicaid, and no insurance, with no corresponding difference in ED charges. Expenditures as a proportion of charges decreased for all insurers over time. Private insurance had the highest expenditure-to-charge ratio in each year.