Using the Health Insurance Policy Simulation Model, this report analyzes four policy options for assessing employers who do not provide affordable health insurance to their workers as Massachusetts brings its health reform law into compliance with the Affordable Care Act (ACA). Overall coverage and costs are similar across all options, but replacing the state's Fair Share Contribution (FSC) requirement with the ACA assessment would eliminate a source of state revenue. Similarly, maintaining the FSC for small employers only would raise one-fifth as much revenue as leaving the current assessment in place.