The objective of this project is to provide timely evidence on patterns of tobacco and alcohol co-use among smokers who use electronic nicotine delivery systems (ENDS) or heated tobacco products (HTP); how these patterns affect smokers’ decisions to reject ENDS/HTP, substitute them for only a few cigarettes, switch exclusively to them, or use them to completely quit using tobacco; and evaluate how excise taxes and tobacco use restrictions in restaurants and bars affect stated preferences for alcohol and impact tobacco and alcohol co-use.