Idaho Smoking Age Changing from 18 to 21 Last year President Donald Trump signed a law changing the federal tobacco sales age from 18 to 21. Here in Idaho, earlier today, The House Health and Welfare Committee approved a measure to bring Idaho up to that standard to match the federal smoking age. Most Idaho stores are already following the federal law and only selling smoking products to individuals over the age of 21. However, The House Health and Welfare Committee say that the state law needs to be updated to match the federal law so there is no confusion or gray area for stores, individuals and law enforcement. This would not, even though there was some confusion, have any affect where adults are able to smoke in Idaho. This just has to do with the age requirement.