<P> From 1976 to 1983 , several states voluntarily raised their purchase ages to 19 ( or , less commonly , 20 or 21 ) , in part to combat drunk driving fatalities . In 1984 , Congress passed the National Minimum Drinking Age Act , which required states to raise their ages for purchase and public possession to 21 by October 1986 or lose 10 % of their federal highway funds . By mid-1988 , all 50 states and the District of Columbia had raised their purchase ages to 21 ( but not Puerto Rico , Guam , or the Virgin Islands , see Additional Notes below ) . South Dakota and Wyoming were the final two states to comply with the age 21 mandate . The current drinking age of 21 remains a point of contention among many Americans , because of it being higher than the age of majority ( 18 in most states ) and higher than the drinking ages of most other countries . The National Minimum Drinking Age Act is also seen as a congressional sidestep of the tenth amendment . Although debates have not been highly publicized , a few states have proposed legislation to lower their drinking age , while Guam has raised its drinking age to 21 in July 2010 . </P>
when did the legal drinking age changed to 21
By mid-1988