Tennessee enforces some of the nation’s strictest DUI laws, which became even more stringent with major updates that took effect on January 1, 2026. In May 2025, the state passed Senate Bill 1400, updating key sections of Titles 39, 40, and 55, Chapter 10. Drivers over 21 remain subject to a “per se” blood alcohol concentration (BAC) limit of 0.08%, but the state can still prosecute individuals for impaired driving even if their BAC falls below this threshold. Your license can be automatically suspended after a DUI arrest in Tennessee, even before a conviction.
What Constitutes a DUI in Tennessee?
Under Tennessee Code § 55-10-401, it is illegal to drive or be in physical control of a vehicle while impaired by alcohol, drugs, or any intoxicating substance. Tennessee DUI laws cover a range of offenses beyond just alcohol-related DUI.
Alcohol DUI
The law applies to drivers 21 and over with a BAC of 0.08% or higher, and zero tolerance limit for those under 21. Tennessee’s DUI laws also allow charges for driving while impaired even below the legal per se limit. Per se means a driver is legally presumed intoxicated based solely on their BAC regardless if there were any visible signs of impaired driving.
Drug DUI
Driving under the influence of illegal drugs, prescription medications, or over-the-counter substances that could impair your ability to operate a vehicle is prohibited. Under Tennessee law, you can be charged with DUI even if the medication was legally prescribed, if this medication affects your ability to drive safely.
Underage DUI
Tennessee enforces a zero-tolerance policy for minors, and penalties can include license suspension, fines, and mandatory education programs.
Aggravated DUI
In Tennessee, an aggravated DUI is a more serious type of driving under the influence, with stiffer penalties. It usually applies when a DUI offense is accompanied by serious aggravating factors, such as:
- Driving under the influence with a passenger under 18 years old.
- A second or subsequent DUI offense may be considered aggravated especially if prior convictions are recent.
- Causing a car accident that results in injury or death to another person.
- A BAC of 0.15% or higher.
Repeat DUI Offenses
Tennessee enforces strict mandatory penalties for repeat DUI offenders, with increasingly severe punishments for second, third, and subsequent convictions.
What is the Legal BAC Limit?
The legal BAC limits are:
- Drivers 21 and older⎯The legal limit is 0.08%. Driving with a BAC at or above this level is considered a per se DUI.
- Drivers under 21⎯Tennessee enforces a zero-tolerance policy for underage drivers.
- Commercial drivers⎯When operating a commercial vehicle, the BAC limit is much lower at 0.04%.
It is important to remember that you can still be charged with a DUI even if your BAC is below the legal limit if a law enforcement officer determines that your driving ability is impaired by alcohol, drugs, or a combination of both.
What Are Penalties for a First-Time DUI Conviction in Tennessee?
A first-time DUI in Tennessee carries serious consequences, and is classified as a Class A misdemeanor. Charges for a first-time DUI could include:
- Jail Time⎯A mandatory minimum of 48 hours in jail. This increases to a minimum of 7 days if your BAC was 0.20% or higher.
- Fines⎯They range from $350 to $1,500.
- License revocation⎯License will be revoked for one year.
- Ignition interlock device⎯A car ignition interlock device may be required.
- Paying restitution to anyone who suffered injury or property damage if the DUI caused an accident.
What Are Penalties for a Second DUI Offense in Tennessee?
A second DUI conviction carries significantly harsher penalties than a first offense. These could include:
- Jail Time⎯A minimum of 45 days in jail, with a maximum of 11 months and 29 days
- Fines⎯They range of $600 to $3,500.
- License revocation⎯License will be revoked for two years.
- Ignition interlock device⎯Tennessee law mandates the use of an ignition interlock device for the entire length of a license revocation.
- Vehicle seizure⎯The court may order your vehicle to be seized.
What Are Penalties for a Third or Subsequent DUI Offense in Tennessee?
For third and subsequent DUI offenses, Tennessee imposes substantially stricter penalties. A third DUI offense requires a mandatory minimum jail sentence of 120 days, fines from $1,100 to $10,000, and a license revocation of three to ten years. A fourth or subsequent offense is a Class E felony and carries a minimum of one year in prison with at least 150 consecutive days served, fines from $3,000 to $15,000, and a license revocation of five years to life.
What is Tennessee’s Implied Consent Law?
Under Tennessee Code § 55‑10‑401, drivers give implied consent to chemical testing for a BAC if law enforcement suspects impairment. Declining a breath, blood, or urine test won’t prevent a DUI charge, and can be used as evidence against you as well as an automatic license suspension.
Do You Need a Lawyer If You Were Hit by a Drunk Driver in Tennessee?
If you were injured by a drunk driver in Tennessee, you may be entitled to compensation for your medical bills, lost wages, pain and suffering, and other damages. Tennessee’s strict DUI laws work in your favor — when a driver is charged or convicted of DUI, that evidence can significantly strengthen your civil claim. However, building a strong case takes time, and critical evidence like police reports, BAC results, and witness statements must be preserved quickly. Timing matters. There are strict deadlines under Tennessee’s statute of limitations for filing a personal injury claim, and the longer you wait, the harder it becomes to secure the evidence you need. At Wettermark Keith, we work on a contingency fee basis — meaning you pay nothing unless we win your case. We have personal injury attorneys in Chattanooga and Knoxville ready to fight for you. Contact us today at (877) 455-4518 for a free case review.
Disclaimer: This blog post is for informational purposes only and does not constitute legal advice. For specific guidance regarding your situation, consult a licensed attorney.
