Health plans for the poor increasingly limit access to specialty hospitals. We investigate the role of adverse selection in generating this equilibrium among private plans in Medicaid. Studying a network change, we find that covering a top cancer hospital causes severe adverse selection, increasing demand for a plan by 50% among enrollees with cancer versus no impact for others. Medicaid’s fixed insurer payments make offsetting this selection, and the contract distortions it induces, challenging, requiring either infeasibly high payment rates or near-perfect risk adjustment. By contrast, a small explicit bonus for covering the hospital is sufficient to make coverage profitable

We provide a new method to analyze discrete choice models with state dependence and individual-by-product fixed effects, and use it to analyze consumer choices in a policy-relevant environment (a subsidized health insurance exchange). Moment inequalities are used to infer state dependence from consumers' switching choices in response to changes in product attributes. We infer much smaller switching costs on the health insurance exchange than is inferred from standard logit and/or random effects methods. A counterfactual policy evaluation  illustrates that the policy implications of this difference can be substantive.

Incomplete health insurance enrollment is a persistent U.S. challenge despite large subsidies. We ask whether hassles built into enrollment systems matter for insurance take-up and targeting. Studying removal of an auto-enrollment policy, we find that a small hassle – a requirement to actively select a health plan to enroll – reduces take-up by 33%, a major impact equivalent to $470 (57%) higher enrollee premiums. Hassles differentially screen out younger, healthier, and poorer people – groups with both low value and costs of insurance. We show that this value-cost correlation – a standard feature of insurance, where risk drives both – may undermine the classic rationale for ordeals' favorable targeting.