INTRODUCTION Although benzodiazepines are primarily considered anxiolytics, some have other indications such as seizures, insomnia, alcohol withdrawal, and tardive dyskinesia.  They are also commonly abused medications, especially the brand name products, alone and in combination with other drugs (e.g. methadone).  They are classified, on the basis of their half lives, into short-, intermediate- and long-acting agents.  The side effects of falling and fractures cause benzodiazepines to be unattractive for elderly patients.  OBJECTIVES: To describe trends in the utilization of, spending on, and average per-prescription spending on benzodiazepines, individually, stratified by half life, and overall, for the U.S. Medicaid programs over the past two decades. METHODS: A retrospective, descriptive analysis was performed using the national Medicaid pharmacy claims database, which has information on outpatient prescription claims. Quarterly prescription counts and reimbursement amounts were calculated for each of the benzodiazepines (branded or generic) reimbursed by Medicaid.  Average per-prescription spending was found by dividing reimbursement by the number of prescriptions. RESULTS: Prescriptions for benzodiazepines among Medicaid beneficiaries increased from 6.15 million in 1991 to 16.70 million in 2009.  Expenditures rose from $108.75 million to $165.79 million over the same time period, implying an average per-prescription price of approximately $10 in 2009. Whereas utilization of long-acting agents remained relatively constant at 1.79 million prescriptions per year, prescriptions for short-acting and intermediate-acting drugs rose from 1.74 million to 4.94 million, and from 2.82 million to 9.91 million, respectively.   Prescriptions for flurazepam have fallen steadily from 439,106 in 1991 to 45,754 in 2009. CONCLUSIONS: Spending on benzodiazepines represents < 1% of Medicaid’s spending on outpatient drugs.  Moreover, due to generic entry for some of the drugs, the percentage rise in spending on benzodiazepines since 1991 (52.5%) was less than the general rate of inflation (57.5%). By its policy of reimbursing for generic, rather than branded, prescriptions, Medicaid reduces the opportunity for abuse.