Under provisions of the Medicare Prescription Drug, Improvement, and Modernization Act of 2003, Medicare-approved discount drug cards became available for purchase June 1, 2004 in California and throughout the country. As little information exists to assess the value of prescription drug discount cards, the California HealthCare Foundation (CHCF) sponsored a Consumers Union analysis of Medicare-approved discount card savings. The results of this analysis, summarized here, provide concrete advice to California consumers about the circumstances under which these cards are most useful.