Industrial customer opt-out is a policy that allows some large customers to opt out of or leave utility-sector energy efficiency programs. When a customer decides to opt out, it no longer participates in these programs and is exempt from paying the utility costs of running them. In this report, we use Ohio as an example to estimate several economic consequences of opt-out. Applying Ohio-specific data across three alternate scenarios, we estimate the increased utility system costs, health-related costs, and lost bill savings that would result from an expanded opt-out policy in the state.