Objectives: To develop a simulation model to predict the effects of different smoking treatment policies on quit rates, smoking rates, and smoking attributable deaths. Methods: We first develop a decision theoretic model of quitting behaviour, which incorporates the decision to quit and the choice of treatment. A model of policies to cover the costs of different combinations of treatments and to require health care provider intervention is then incorporated into the quit model. The policy model allows for the smoker to substitute between treatments and for policies to reduce treatment effectiveness. The SimSmoke computer simulation model is then used to examine policy effects on smoking rates and smoking attributable deaths. Results: The model of quit behaviour predicts a population quit rate of 4.3% in 1993, which subsequently falls and then increases in recent years to 4.5%. The policy model suggests a 25% increase in quit rates from a policy that mandates brief interventions and the coverage of all proven treatments. Smaller effects are predicted from policies that mandate more restricted coverage of treatments, especially those limited to behavioural treatment. These policies translate into small reductions in the smoking rate at first, but increase to as much as a 5% reduction in smoking rates. They also lead to substantial savings in lives. Conclusions: Tobacco treatment policies, especially those with broad and flexible coverage, have the potential to increase smoking cessation substantially and decrease smoking rates in the short term, with fairly immediate reductions in deaths.M uch of the focus of recent tobacco control policies has been on youth prevention, 1 through such policies as media campaigns, reducing tobacco sales to youth, and school education programmes. These policies take considerable time to reduce overall smoking rates and smoking related deaths.2 Reducing the number of current smokers is necessary, however, to improve health in the immediate future. If current smokers quit, many of the health effects associated with smoking can be reversed. The recently released and updated Department of Health and Human Services guidelines 5 recommend that health care workers provide brief intervention and follow up, and that they advise the use of pharmacotherapy combined with behavioural treatment. Considerable research documents the effectiveness and cost effectiveness of treatment for tobacco use and dependence. Yet, access to treatment and involvement of health care workers is limited. Minimal interventions are not routinely provided by many health care providers.6 7 Less than half of managed care operations fully cover cessation classes or telephone counselling, and pharmacotherapy is rarely covered.8 Even government payers, such as Medicaid and Medicare, often provide limited or no coverage. Greater access to smoking cessation treatments and involvement of health care providers has the potential to increase treatment use.5 10-13 In this paper, we present a simulation model of tobacco treatment ...