In Tennessee, it is illegal for a driver at least 21 years old to drive with a blood alcohol concentration (BAC) of ______ or above.

In most states, including Tennessee, it is illegal to drive with a blood alcohol concentration (BAC) of 0.08% or above. (0.08% means eight drops of alcohol for every 10,000 drops of blood in a person's body.) In Tennessee, it is illegal for a driver under 21 years of age to drive with a BAC of 0.02% or above.