While vaccination rates in the United States are high — generally over 90 percent — rates of exemptions have been going up, and preventable diseases coming back. Aside from their human cost and the financial cost of treatment imposed on those who become ill, outbreaks impose financial costs on an already burdened public health system, diverting resources from other areas. This article examines the financial costs of non-vaccination, showing how high they can be and what they include. It makes a (...) case for requiring those who do not vaccinate to cover the costs of outbreak caused by their choice. Such recouping is justified because the choice not to vaccinate can easily be seen as negligent. But even if it is not, that choice involves imposing costs on others, and there are good reasons to require the actors to internalize those costs. The article proposes alternative statutory and regulatory schemes to cover the costs imposed on the public purse, focusing on no-fault mechanisms. We consider both ex ante mechanisms like a tax or a fee that will go into a no-fault fund to cover the costs and ex post mechanisms like a statutory authorization for recoupment of those costs by health officials. (shrink)