The MO HealthNet Pharmacy Program oversees outpatient prescription drug reimbursement for fee-for-service eligibles. Effective January 1, 1991, the Omnibus Budget Reconciliation Act of 1990 (OBRA-90) pharmacy provisions significantly expanded the coverage to include reimbursements for all drug product of manufacturers who have entered into a rebate agreement with the Federal Department of Health and Human Services (HHS) and that are dispensed by qualified providers. States have the authority for certain exceptions and to exclude from coverage certain specified categories of drugs. In addition, OBRA-90 included provisions requiring both a prospective and retrospective drug use review program.