Capitated, performance-based payments to primary care physicians (PCPs) to provide for a panel of patients could empower efficient, quality care provision if 1) initial payments are risk adjusted, and 2) we can create credible performance-based payment adjustments (bonuses) to reward lower-than-expected use of specialist and intensive services and better health outcomes. We address the issue of bonus payments using “expected number of potentially avoidable emergency department (ED) visits” as an example of a utilization target that PCPs could be held accountable for. We propose (and simulate the consequences of) a framework for a) defining potentially avoidable ED visits, b) producing risk-adjusted expected numbers of such visits for physician panels, and c) establishing a bonus structure that creates incentives for reductions in apparently inefficient emergency department use.