For other meanings, see legal drinking age. The National Minimum Drinking Age Act of 1984 (23 U.S.C. § 158) was passed on July 17, 1984. It punished every state that allowed persons below 21 years to purchase and publicly possess alcoholic beverages by reducing its annual federal highway apportionment by ten percent.s the minimum legal drinking age was still left to the discretion of the state, the act did not violate the 21st amendment which reserved the right to regulate alcohol for all responsibilities not specifically appointed to the federal government to the states.