If you get a DUI at 18, you are prosecuted in adult criminal court under a stricter zero-tolerance blood alcohol limit than drivers 21 and over, and a conviction creates a permanent criminal record along with license loss, roughly five figures in direct costs, sharply higher insurance for years, and complications for college, jobs, and travel. In 44 states, juvenile jurisdiction ends at 17, so the case runs through the same courts and carries the same lasting record as it would for any adult.
Why 18-Year-Olds Get Hit Harder
Federal law requires every state to set the BAC limit for drivers under 21 at 0.02% or lower.1Office of the Law Revision Counsel. 23 USC 161 – Operation of Motor Vehicles by Intoxicated Minors For drivers 21 and over, the standard limit is 0.08%.2Office of the Law Revision Counsel. 23 USC 163 – Safety Incentives to Prevent Operation of Motor Vehicles by Intoxicated Persons A single beer can push an 18-year-old over the line. Some states set the underage threshold even lower, at 0.01% or any detectable amount.
Under zero tolerance, the prosecution doesn’t need to prove you were impaired. If the chemical test shows a BAC at or above the underage limit, that reading alone is enough to convict. The number is the number, and most underage DUIs are nearly impossible to fight on the merits once that reading exists.
What Happens the Night of the Arrest
After the traffic stop, you’re taken to a police station for booking, which includes fingerprints and a photograph. Your vehicle is impounded at your expense. Release usually requires posting bail, or in lower-level cases a written promise to appear.
The sharpest early blow is the administrative license suspension. This is a civil action by the state’s motor vehicle agency, separate from the criminal case. The arresting officer forwards paperwork to the DMV, which suspends your driving privileges on its own schedule. You typically get a temporary permit valid for around 30 days, then the suspension kicks in. You can lose the ability to drive before you ever see a judge.
Should You Refuse the Breath or Blood Test?
Every state has an implied consent law: by driving on public roads, you’ve already agreed to submit to chemical testing when an officer has probable cause. Refusing doesn’t make the case go away. It triggers an automatic license suspension that is usually longer than the suspension for failing the test, and the refusal itself can be used as evidence against you at trial.3Justia. Birchfield v. North Dakota, 579 US (2016) For most 18-year-olds, refusing makes the situation worse, not better.
Criminal Penalties for a First Offense
Because you’re in adult court, a conviction creates a permanent criminal record. A first-offense DUI is typically a misdemeanor, with penalties that commonly include:
- Jail time ranging from a few days to six months, though first offenders without aggravating factors often get probation rather than actual time in custody.
- Court fines that vary widely by jurisdiction, commonly from several hundred to several thousand dollars, with added surcharges and court costs.
- Probation of one to three years, usually with an alcohol education program, random testing, community service, and sometimes a victim impact panel.
Penalties escalate quickly with aggravating factors. A BAC well above the limit, an accident that injures someone, or a minor in the car can each bump the charge up. Some aggravators turn a misdemeanor into a felony, with prison time measured in years.
What It Really Costs
The courtroom fine is only a slice of the total. Added up from arrest through the end of probation, a first DUI typically starts around $10,000 and can climb well past that. The money goes to:
- Towing and impound, often $150 to $300 or more.
- Bail, from a few hundred to several thousand dollars depending on jurisdiction and circumstances.
- Private defense attorney fees, typically $1,000 to $10,000 for a first offense.
- Court-mandated alcohol education classes, usually several hundred dollars.
- Monthly probation supervision fees across one to three years.
- License reinstatement fees paid to the DMV.
- Ignition interlock installation plus monthly lease and calibration, typically $500 to $1,600 over the required period.
- Insurance increases, the biggest long-term cost.
For someone working part-time or starting college, this lands at the worst possible moment. The costs don’t all arrive at once, but they don’t go away quickly either.
What Happens to Your License
A first-offense DUI conviction generally brings a license suspension of 90 days to one year, depending on the state and your BAC. After part of the suspension, many states let you apply for a restricted or hardship license that permits driving to work, school, or court-ordered treatment.
In 31 states plus the District of Columbia, getting even a restricted license requires installing an ignition interlock device on any vehicle you drive.4National Conference of State Legislatures. State Ignition Interlock Laws The device demands a clean breath sample before the engine will start, and you pay for all installation, lease, and calibration fees. For a first offense, the interlock requirement typically lasts six months to a year.
Most states also require an SR-22 filing, a certificate your insurer sends to the DMV confirming you carry liability coverage. The requirement can last up to five years and flags you as a high-risk driver that whole time. If your policy lapses while the SR-22 is active, the DMV is notified and your license is suspended again.
Insurance Aftermath
This is where the long-term cost really stacks up. After a DUI conviction, insurers reclassify you as high-risk. Rate analyses show the average annual premium roughly doubles, climbing by about $2,300 per year compared to a driver with a clean record. For an 18-year-old whose premiums are already elevated by age and inexperience, the combined effect can make coverage nearly unaffordable.
The increase isn’t short-lived. Most insurers look back three to five years when pricing a policy, and some states keep the DUI on your driving record longer. Between the higher premiums and the SR-22 filing, insurance costs alone can exceed $10,000 over the years following one conviction.
College, Jobs, and the Military
A DUI conviction won’t automatically kill your federal student aid. The FAFSA no longer asks about drug convictions, and a standard alcohol-related DUI was never a disqualifying offense for federal grants and loans.5Federal Student Aid. Criminal Convictions and Financial Aid Eligibility Private scholarships and university-run aid programs can have their own conduct rules, so a misdemeanor conviction may still affect those awards.
Admissions is trickier. The Common Application dropped its blanket criminal history question several years ago, but individual colleges can still ask about convictions on supplemental forms. A disclosed DUI isn’t an automatic rejection, but it adds friction, especially for competitive programs. Campus housing applications may ask too.
Employment takes a hit as well. Background checks are standard, and a DUI on an adult record raises flags for any job involving driving, heavy equipment, or a professional license. Military enlistment usually requires a moral waiver after a DUI, and not every branch will grant one.
Travel to Canada
Canada treats impaired driving as a serious criminal offense, and a U.S. DUI conviction can make you inadmissible at the border under the Immigration and Refugee Protection Act.6Justice Laws Website. Immigration and Refugee Protection Act – Section 36 – Inadmissibility If less than five years have passed since you finished your sentence (including probation), you’d need to apply for a Temporary Resident Permit just to visit. After five years, you can apply for criminal rehabilitation. After ten years with a single conviction, you may be considered rehabilitated by the passage of time. A conviction at 18 can restrict Canadian travel through your mid-to-late twenties.
Can You Get It Off Your Record Later?
Expungement depends entirely on your state. Some allow expungement of a first-offense misdemeanor DUI after a waiting period and completion of all sentence requirements. Others prohibit DUI expungement no matter how much time passes. A few offer record sealing, which hides the conviction from most background checks without erasing it.
Where expungement is available, the waiting period is usually several years after probation ends, and you’ll need a clean record during that time. The process typically requires filing a petition and sometimes a hearing. Check your state’s rules as soon as the case resolves, even if you can’t file for years. Knowing the timeline gives you something concrete to work toward.