In fiscal years 2009 through 2011, the most expensive 5% of Medicaid-only enrollees accounted for 48% of Medicaid expenditures. The least expensive 50% of Medicaid-only enrollees accounted for less than 8% of expenditures. Almost 12% of Medicaid enrollees during each fiscal year had no expenditures over this time period. Of those in the most-expensive 5% of Medicaid-only enrollees, over the three-year period an average of 51.3% had a mental health condition and 19.19% had a substance abuse disorder. In contrast, among all Medicaid enrollees over the three-year period, an average of 12 . . .