The National Minimum Drinking Age Act of 1984 states that revenue will be withheld from states that allow the purchase of alcohol by anyone under the age of 21. Prior to the effective date of that Act, the drinking age varied from state to state. Some states do not allow those under the legal drinking age to be present in liquor stores or in bars (usually, the difference between a bar and a restaurant is whether food is being served). Contrary to popular belief, since the act went into law, few states specifically prohibit minors and young adults from consuming alcohol in private settings. As of January 1, 2007, 14 states and the District of Columbia ban underage consumption outright, 19 states do not specifically ban underage consumption, and an additional 17 states have family member and/or location exceptions to their underage consumption laws.
Federal law explicitly provides for religious, medical, employment and private club possession exceptions; as of 2005, 31 states have family member and/or location exceptions to their underage possession laws. However, non-alcoholic beer in many (but not all) states, such as Idaho, Texas, and Maryland, is considered legal for minors (those under the age of 21).[14]
By a judge's ruling, South Carolina appears to allow the possession and consumption of alcohol by those 18 to 20 years of age,[15] though a circuit court judge said otherwise.