An understanding of the costs associated with foodborne illnesses is important to policy makers for prioritizing resources and assessing whether proposed interventions improve social welfare. At the national level, measured costs have been used by federal food safety regulatory agencies in regulatory impact analyses. However, when costs differ across states, use of national cost-of-illness values for state-based interventions will lead to biased estimates of intervention effectiveness. In this study, the costs of foodborne illness at the state level were estimated. Using a more conservative economic model, the average cost per case ranged from $888 (90% credible interval [CI], $537 to $1,419) in West Virginia to $1,766 (90% CI, $1,231 to $2,588) in the District of Columbia. A less conservative model generated average costs per case of $1,505 (90% CI, $557 to $2,836) in Kentucky to $2,591 (90% CI, $857 to $5,134) in Maryland. Aggregated across the states, the average national cost of foodborne illness was estimated as $55.5 billion (90% CI, $33.9 to $83.3 billion) using the conservative model and $93.2 billion (90% CI, $33.0 to $176.3 billion) using the enhanced model.