Laws are constantly changing and evolving – often in response to current events and new technology. Tennessee’s laws surrounding driving impaired are different. Staying up-to-date with the state laws around DUIs can help you stay ahead of any possible violations or unknowingly running afoul of the law. As criminal defense attorneys well-versed in DUI laws, it’s part of our commitment at PNC Law to stay on top of such changes.
This article goes over some of the changes to DUI law that are either already in effect or will be soon.
Lowered BAC Threshold for Vehicular Assault and Homicide
A law lowering the blood alcohol concentration (BAC) threshold from 0.20% to 0.15% for aggravated vehicular assault and homicide went into effect July 1, 2025. Now, you could be charged with aggravated vehicular assault or homicide if your BAC is 0.15% or more and you are involved in a crash that results in serious bodily injury or death of another, or if you have previous DUI charges on your record. This change means that someone who once would’ve been facing a misdemeanor DUI charge if they blew a 0.15% would now face a felony charge and mandatory jail time. For context, the average-sized man would reach 0.15% BAC after seven beers in two hours, while the average-sized woman would reach it after five beers in two hours.
It’s worth noting that this does not affect the 0.08% legal limit for a DUI. This change is intended to crack down on the most dangerous instances of driving impaired.
Increased Penalty for Refusing a Breathalyzer and Blood Tests
Under the law of implied consent, when you receive your driver’s license, you have automatically consented to any requested breathalyzer or blood test. Refusing one is considered unlawful and could result in your license being suspended.
The new law, which goes into effect on January 1, 2026, extends the license for refusing a breathalyzer from 12 months to 18 months. Additionally, the implied consent violation will no longer be dropped if a warrant is later obtained for your blood. Regardless of whether or not your blood was obtained when requested, your license will still be suspended.
New Oral Fluid Testing
The implied consent law got another change this year that went into effect in May of 2025. After pressure to figure out a way to detect fast metabolizing drugs like THC and opioids, the Tennessee legislature passed an amendment to the implied consent law that allowed for saliva tests in addition to blood and breathalyzer tests. Therefore, as with denying a breathalyzer or blood test, refusing to provide a saliva test is considered unlawful.
After swabbing both cheeks, an officer will insert the swab into a machine that will light up with a numeric panel if you exceed the per se limits for any target drug. Important to note that a positive screening does not automatically mean a DUI charge or admissible evidence of impairment. A blood test will still be requested, which will be used to confirm the saliva test results.
Facing a DUI Charge? Let Us Help
A DUI arrest can put your license, your freedom, and your future at risk, but you don’t have to face it alone. Our experienced DUI defense attorneys know how to challenge the evidence, protect your driving privileges, and fight for the best possible outcome. If you or someone you know has been arrested for a DUI, contact PNC Law at (615) 785-2000 or philip@tncriminaldefenseattorney.com.