Tobacco use is the leading cause of preventable disease and death in the United States. Increasing the unit price on tobacco products is the most effective tobacco prevention and control measure. Illicit tobacco trade (illicit trade) undermines high tobacco prices by providing tobacco users with cheaper-priced alternatives. In the United States, illicit trade primarily occurs when cigarettes are bought from states, jurisdictions, and federal reservation land with lower or no excise taxes, and sold in jurisdictions with higher taxes. Applying tax stamps to tobacco products, which provides documentation that taxes have been paid, is an important tool to combat illicit trade. Comprehensive tax stamping policy, which includes using digital, encrypted ("high-tech") stamps, applying stamps to all tobacco products, and working with tribes on stamping agreements, can further prevent and reduce illicit trade. This report describes state laws governing tax stamps on cigarettes, little cigars (cigarette-sized cigars), roll-your-own tobacco (RYOT), and tribal tobacco sales across the United States as of January 1, 2014, and assesses the extent of comprehensive tobacco tax stamping in the United States. Forty-four states (including the District of Columbia [DC]) applied traditional paper ("low-tech") tax stamps to cigarettes, whereas four authorized more effective high-tech stamps. Six states explicitly required stamps on other tobacco products (i.e., tobacco products other than cigarettes), and in approximately one third of states with tribal lands, tribes required tax stamping to address illicit purchases by nonmembers. No U.S. state had a comprehensive approach to tobacco tax stamping. Enhancing tobacco tax stamping across the country might further prevent and reduce illicit trade in the United States.