Medicare Part D prescription drug plans specifically exclude coverage of benzodiazepines, largely because of concerns over safety and inappropriate use. However, even before Part D plans were implemented in January 2006, concerns were raised about the exclusion's impact on people with anxiety disorders, the population most likely to be adversely affected. To investigate the impact, Michael K. Ong, M.D., Ph.D., and colleagues analyzed claims data for more than 8,300 Medicare enrollees with new diagnoses of anxiety. The authors found that the benzodiazepine exclusion resulted in significantly increased use and days' supply of nonbenzodiazepine psychotropic drugs, specifically antidepressants and other anxiolytics, and in an overall decline in claims for psychotropic medications. The overall decline may reflect a reduction in the treatment of anxiety, the authors note, because they did not find evidence of an increase in use of outpatient care to substitute for psychotropic medications. Expenditures for psychotropic medications increased even though fewer claims were filed, reflecting the higher costs of some nonbenzodiazepine alternatives (page 637). In Taking Issue, Martha Sajatovic, M.D., draws parallels between the benzodiazepine exclusion and the failed U.S. policy of Prohibition (page 627).