PurposeWe examined the influence of tobacco control program funding, smoke-free air laws, and cigarette prices on young adult smoking outcomes. MethodsWe use a natural experimental design approach that uses the variation in tobacco control policies across states and over time to understand their influence on tobacco outcomes. We combine individual outcome data with annual state-level policy data to conduct multivariable logistic regression models, controlling for an extensive set of sociodemographic factors. The participants are 18- to 25-year-olds from the 2002–2009 National Surveys on Drug Use and Health. The three main outcomes are past-year smoking initiation, and current and established smoking. A current smoker was one who had smoked on at least 1 day in the past 30 days. An established smoker was one who had smoked 1 or more cigarettes in the past 30 days and smoked at least 100 cigarettes in his or her lifetime. ResultsHigher levels of tobacco control program funding and greater smoke-free-air law coverage were both associated with declines in current and established smoking (p < .01). Greater coverage of smoke-free air laws was associated with lower past year initiation with marginal significance (p = .058). Higher cigarette prices were not associated with smoking outcomes. Had smoke-free-air law coverage and cumulative tobacco control funding remained at 2002 levels, current and established smoking would have been 5%–7% higher in 2009. ConclusionsSmoke-free air laws and state tobacco control programs are effective strategies for curbing young adult smoking.