The Medicare Prescription Drug, Improvement and Modernization Act of 2003 will provide drug coverage to older adults through a variety of mechanisms, including stand-alone prescription drug benefits. Variation in cost-sharing and utilization controls is permitted, leading potentially to a wide variety of prescription benefit plans. However, little is known regarding the manner in which beneficiaries will integrate information to form plan evaluations.The objectives of this study were to assess and compare the use of compensatory and configural judgment models in older adults' evaluations of drug benefit plans.Three focus groups were conducted with a total of 19 seniors to elicit relevant drug plan attributes. A separate group of 32 seniors then judged the suitability of 48 drug benefit profiles based on these attributes. Within-subjects regression analysis was used to reveal each participant's judgment policy.Focus groups suggested that copayment, premium, deductible, formulary use, and mail-service use were relevant plan attributes. Regression analyses showed that while most participants used compensatory judgment models in evaluation formation, 12 (37.5%) subjects used conjunctive judgment models.Configural judgment processes are used frequently by older adults when evaluating drug benefit plans. Future research using more fine-grained techniques (eg, process tracing) might help further elucidate judgment processes in this context.