is there a legal age to smoke cigarettes
The federal law requires states to have a minimum age of 18 years for sale/purchase of tobacco products (21 U.S.C. § 387f. (3)(a)(ii)). State and local laws may extend this ban and also prohibit supply, possession and consumption to/by person underage, or increase the age beyond 18. However, most states do not directly ban the consumption of tobacco by a minor. The federal law requiring states to have a minimum purchasing age at 18 is enforced by withholding FEMA disaster and non-disaster grants from states that have purchasing ages under 18, and currently no state falls under that category.
Smoking age