Rates of age verification for cigarette and e-cigarette purchases as a function of state T21 laws before and after implementation of the federal T21 law in the United States.

Current findings suggest that variations in regulations and gaps in enforcement may hinder the potential impact of increasing the minimum legal sales age, which ultimately may undermine the promise of such policies, specifically with regard to preventing tobacco use among the underage. Therefore, it is crucial to monitor retailer compliance with T21 laws and evaluate their efficacy to increase/improve ID checks, minimize illegal sales, and curb underage use of tobacco. Relatedly, particular attention to enforcement efforts that may promote compliance is warranted.