Tennessee’s DUI laws make it illegal to drive with a blood alcohol concentration of 0.08% or higher, and a first conviction carries a mandatory minimum of 48 hours in jail, fines starting at $350, and a one-year license revocation. Penalties climb sharply with each subsequent offense, a fourth DUI becomes a felony, and no DUI conviction can ever be expunged from your record in Tennessee.
The Legal Limit for Impairment
The standard threshold is 0.08% BAC. You don’t have to be visibly impaired or fail a field sobriety test — hitting that number alone is enough to convict.1Justia. Tennessee Code 55-10-401 – Driving Under the Influence Prohibited
Two groups face lower limits. Commercial vehicle operators are legally impaired at 0.04%, half the standard.1Justia. Tennessee Code 55-10-401 – Driving Under the Influence Prohibited Drivers under 21 fall under a near-zero-tolerance rule of 0.02%, which means a single drink can put them over.2Justia. Tennessee Code 55-10-415 – Underage Driving While Impaired – Penalties
Alcohol isn’t the only trigger. Tennessee also prohibits driving while impaired by marijuana, controlled substances, prescription medications, or any combination that affects your ability to drive safely.1Justia. Tennessee Code 55-10-401 – Driving Under the Influence Prohibited There’s no set concentration for a drug DUI. Prosecutors have to prove the substance actually impaired your driving; simply having a drug in your system isn’t enough under the statute, though it will be used as evidence. When drug impairment is suspected, officers typically request a blood draw, since breath tests can’t detect anything other than alcohol.
Penalties for a First Offense
A first DUI is a Class A misdemeanor, the most serious misdemeanor class in Tennessee. The mandatory minimum jail sentence is 48 consecutive hours, and the maximum is 11 months and 29 days. If your BAC was 0.15% or higher, the floor jumps to seven consecutive days.3Justia. Tennessee Code 55-10-402 – Penalty for Violations of Section 55-10-401
Fines run from $350 to $1,500, though that’s only the starting figure. Court costs often add another $500 to $1,000, and towing, bail, DUI education, and higher insurance premiums push the real total into the thousands.
Your license is revoked for one year. A restricted license allowing travel to work, school, or court-ordered programs may be available, but the court can require you to install an ignition interlock device at your own expense as a condition of that restricted license.4Justia. Tennessee Code 55-10-417 – Ignition Interlock Devices
Penalties for Repeat Offenses
Tennessee escalates the penalties dramatically with each subsequent conviction. Mandatory minimum jail sentences are served day-for-day, so no early release or good-behavior credits apply to that portion.
Second Offense
A second DUI is still a Class A misdemeanor, but the mandatory minimum jumps to 45 consecutive days in jail, with the same maximum of 11 months and 29 days.3Justia. Tennessee Code 55-10-402 – Penalty for Violations of Section 55-10-401 Fines range from $600 to $3,500, and your license is revoked for two years. The vehicle used in the offense is subject to seizure and forfeiture if the prior DUI conviction happened within the preceding five years.5Justia. Tennessee Code 55-10-414 – Seizure and Forfeiture of Vehicles
Third Offense
A third DUI remains a Class A misdemeanor. The mandatory minimum climbs to 120 consecutive days in jail.3Justia. Tennessee Code 55-10-402 – Penalty for Violations of Section 55-10-401 Fines range from $1,100 to $10,000, license revocation runs three to ten years, and vehicle forfeiture is still on the table. Courts routinely order substance abuse treatment and ongoing judicial supervision at this level.
Fourth or Subsequent Offense
A fourth DUI crosses from misdemeanor to Class E felony. That means a prison sentence of one to six years rather than county jail time, and a permanent felony record that affects employment, housing, professional licensing, and firearms rights. Vehicle forfeiture applies here as well.5Justia. Tennessee Code 55-10-414 – Seizure and Forfeiture of Vehicles
DUI With Injury, Death, or a Child in the Vehicle
When impaired driving causes serious bodily injury, the charge becomes vehicular assault, a Class D felony. The mandatory minimum jail time mirrors the DUI structure: 48 consecutive hours for a first alcohol-related offense, 45 consecutive days with one prior, and 120 consecutive days with two priors. License revocation runs from one year for a first conviction up to five years for a fourth or subsequent one.6Justia. Tennessee Code 39-13-106 – Vehicular Assault
If someone dies, the charge is vehicular homicide by intoxication, a Class B felony carrying 8 to 30 years. License revocation runs three to ten years upon conviction.7FindLaw. Tennessee Code 39-13-213 – Vehicular Homicide
The most severe charge is aggravated vehicular homicide, a Class A felony carrying 15 to 60 years. It applies when a DUI-related death occurs and the driver has two or more prior alcohol-related convictions, a prior vehicular homicide conviction, or a BAC of 0.20% or higher combined with at least one prior alcohol-related conviction.8Justia. Tennessee Code 39-13-218 – Aggravated Vehicular Homicide
Driving under the influence with a passenger under 18 adds 30 days of mandatory jail time on top of the base sentence for your offense level. Recent amendments taking effect in 2025 and 2026 further tighten the rules: the BAC threshold for aggravated vehicular assault and homicide drops from 0.20% to 0.15% when a child is involved, refusing a chemical test with a child in the vehicle adds six months to the license suspension, and courts may order mandatory mental health evaluations for certain offenders when a child was endangered.
Implied Consent and Chemical Testing
By driving on Tennessee roads, you have already consented to chemical testing if an officer has probable cause to believe you’re impaired. The state’s implied consent law covers breath tests, blood tests, or both.9Justia. Tennessee Code 55-10-406 – Breath and Blood Tests to Determine Alcohol or Drug Content
Before requesting a test, the officer must tell you what happens if you refuse: the court will suspend your license, and you may be required to use an ignition interlock device if you’re ultimately convicted of DUI. If the officer fails to give this warning, the court loses authority to impose those specific consequences for refusal.9Justia. Tennessee Code 55-10-406 – Breath and Blood Tests to Determine Alcohol or Drug Content
Refusing a test after being properly warned is itself a chargeable violation. And refusing doesn’t necessarily keep the state from getting your blood, because officers can obtain a search warrant for a blood draw.
License Revocation and Getting Back on the Road
Every DUI conviction triggers license revocation. The length depends on your history:
- First offense: one year
- Second offense: two years
- Third offense: three to ten years
Your license stays revoked until the Tennessee Department of Safety actively reinstates it. The clock does not simply expire. You’ll need to pay a reinstatement fee, provide proof of financial responsibility (SR-22 insurance), and meet any other conditions the court set.10Tennessee Department of Safety. Do I Need SR-22 Insurance
SR-22 is a certificate your insurer files with the state confirming you carry the minimum required liability coverage. You must maintain it for the entire revocation period. If your insurance lapses, the insurer notifies the state, and your license returns to revoked status.
An ignition interlock device prevents your vehicle from starting unless you blow into a sensor and register below 0.02% BAC. Courts can order an interlock for any DUI conviction, and in certain cases, particularly repeat offenses or high-BAC cases, the device is mandatory under state law. The cost falls entirely on the offender; the statute bars use of public indigency funds to pay for it.4Justia. Tennessee Code 55-10-417 – Ignition Interlock Devices Installation runs roughly $75 to $150, and monthly lease and calibration fees range from $60 to $100, so a year with the device can easily exceed $1,000. Tampering with or trying to bypass the device brings additional penalties, including extended installation periods or full revocation of your restricted driving privileges.
Consequences for Commercial Drivers
A DUI hits commercial drivers especially hard. The legal BAC limit while operating a commercial motor vehicle is 0.04%, half the standard.1Justia. Tennessee Code 55-10-401 – Driving Under the Influence Prohibited A DUI in your personal vehicle also disqualifies your commercial driver’s license.
A first offense disqualifies your CDL for at least one year, or three years if you were hauling hazardous materials. A second alcohol-related conviction results in lifetime CDL disqualification. For anyone whose livelihood depends on a CDL, that second conviction is effectively career-ending.
Federal rules add another layer. The FMCSA Drug and Alcohol Clearinghouse records all violations, and a driver with a recorded violation cannot perform safety-sensitive functions until completing a return-to-duty process, which includes evaluation by a substance abuse professional, completion of recommended treatment, and a negative return-to-duty test.11Drug and Alcohol Clearinghouse. The Return-to-Duty Process and the Clearinghouse Future employers can see the violation in the Clearinghouse, making work harder to find even after reinstatement.
The Real Cost of a Conviction
The court fine is the smallest piece of what a first-offense DUI actually costs:
- Court fine of $350 to $1,500
- Court costs and fees of $500 to $1,000 or more
- Bail and towing, often several hundred dollars
- DUI education program, typically required and paid out of pocket
- Ignition interlock device, $1,000 or more per year if required
- License reinstatement fee before driving privileges are restored
- SR-22 insurance for the full revocation period, at premiums 50% to 200% above your pre-conviction rate
- Attorney fees, $1,000 to $5,000 or more for a private defense attorney
Insurance is where the damage compounds. A DUI conviction typically pushes auto premiums up by 50% to over 200%, and that increase persists for years. The SR-22 filing requirement lasts the length of your revocation period, and many insurers surcharge DUI-convicted drivers for three to five years after reinstatement. Over that timeframe, the added insurance cost alone can exceed the total of every other expense combined.
A DUI Stays on Your Record for Life
Tennessee explicitly excludes DUI convictions from expungement eligibility. The state’s expungement statute lists violations of TCA 55-10-401 among the misdemeanors that can never be cleared.12Justia. Tennessee Code 40-32-101 – Destruction or Release of Old Records Every DUI stays visible on background checks indefinitely and counts toward enhanced penalties if you’re charged again.
The collateral effects reach well beyond the courtroom. A DUI on your record can affect employment applications, professional licensing, custody proceedings, and housing. A felony DUI from a fourth or subsequent offense also strips firearms rights and carries the full range of consequences that come with a felony record.
International travel catches many people off guard. Canada treats DUI as a serious crime and has full access to FBI criminal databases. A single conviction can result in denial of entry at the Canadian border, regardless of whether the offense was a misdemeanor. Since December 2018, a DUI no longer qualifies for automatic deemed rehabilitation after ten years. Travelers with a DUI may need to apply for a Temporary Resident Permit for short visits or petition for Criminal Rehabilitation, a process requiring at least five years to have passed since completing the full sentence, including all fines and probation.