How does managed care, through restrictions on access, affect utilization? What specific plan attributes influence access and utilization? While other work has examined utilization relative to broad categories of plans (e.g., HMOs, PPOs, POSs), Pravin Trivedi, Ph.D., of Indiana University looked at specific plan characteristics, such as whether members are required to sign up with a certain provider to whom they must go for all routine care, whether they need approval or a referral to see a specialist, whether the plan has a list of preferred providers, and whether the plan pays for any of the costs of visits to doctors not associated with the plan. Using data from the CTS’ Household and followback surveys, the researchers studied the determinants of an individual’s selection of plans with particular attributes. The researchers also examined how restrictions on access affect utilization while allowing for self-selection and explored differences in what the members reported and what insurers reported.