This edition provides data on Medicaid prescription drug usage and costs and trends from 2013 to 2015. Each data table shows national totals and subtotals for three groups of states: non-expansion states, initial Medicaid expansion states (those implementing Medicaid expansion in January 2014), and subsequent expansion states. The tables show all Medicaid-paid pharmacy volume, including prescriptions paid by Medicaid MCOs and those paid in the Medicaid fee-for-service setting. Tables differentiate pre-rebate and post-rebate spending.