Legal BAC Limits by State

Forty-nine states set the legal BAC limit at 0.08% for drivers aged 21 and over. Utah bucks the trend with a stricter 0.05%. But the 0.08% figure tells only part of the story — zero-tolerance laws for underage drivers, reduced CDL limits, and enhanced penalty thresholds add layers of complexity.

Below is a complete reference table for every state, followed by detailed explanations of each category of limit. Use our BAC Calculator to estimate your blood alcohol level based on your drinks, weight, and time.

All 50 States: BAC Limits at a Glance

The Standard 0.08% Limit

Congress forced the issue in 2000 with the Department of Transportation Appropriations Act: adopt 0.08% or lose your federal highway money. Every state and the District of Columbia fell in line by October 2004, which is how a patchwork of limits — some as high as 0.15% in earlier decades — collapsed into a single nationwide standard that most drivers can recite from memory.

Before federal standardization, limits varied considerably. Many states used 0.10% as the threshold through the 1990s, and some had even higher limits in earlier decades. MADD fought for years to push 0.08% into law, backed by research showing meaningful impairment at levels below 0.10%.

NHTSA's Drug and Alcohol Crash Risk Study — led by Blomberg and colleagues across Long Beach and Fort Lauderdale — measured crash odds at various BAC levels and found the risk at 0.08% is roughly four times higher than sober driving, which is a steeper jump than most people expect from "just a couple drinks." See our drunk driving statistics page for the full breakdown. At 0.05% the risk had already doubled, which is part of why the NTSB keeps pushing for a lower national limit.

Utah's 0.05% Limit

Utah rolled out a 0.05% BAC limit effective December 30, 2018, making it the only state in the nation below 0.08%. Critics warned the change would punish casual drinkers and hurt the restaurant industry.

NHTSA's February 2022 evaluation of the law told a different story: Utah's fatal crash rate dropped 19.8% and the fatality rate fell 18.3% in 2019 — the first full year under the new limit — even as vehicle miles traveled went up. The study also found 22% more drinkers opted for sober rides or rideshares instead of driving. The NTSB has recommended all states adopt 0.05%, pointing to over 100 countries already using this threshold. As of 2026, no other US state has followed Utah's lead, though several have introduced legislation.

Zero Tolerance: Under-21 Laws

All 50 states enforce zero-tolerance laws for drivers under the legal drinking age of 21. These laws set the BAC limit for minors at 0.00%, 0.01%, or 0.02% — making it illegal to operate a vehicle with any measurable alcohol in their system.

The slight variation exists because some states set the threshold at 0.02% to account for breathalyzer inaccuracies, trace alcohol from mouthwash or medication, or natural fermentation in the digestive system. California and New Jersey use 0.01%, while Illinois, Maine, Minnesota, and Oregon enforce a hard 0.00%.

First-time offenders typically face automatic license suspension (often 30 days to 1 year), fines, mandatory alcohol education programs, and community service. In many states, even a minimal-BAC zero-tolerance violation results in a DUI on the minor's record.

CDL Limits: 0.04% for Commercial Drivers

Commercial driver's license (CDL) holders face a stricter 0.04% BAC limit when operating a commercial motor vehicle — exactly half the standard threshold. This covers truck drivers, bus drivers, hazmat transporters, and anyone else behind the wheel of a vehicle that requires a CDL.

The FMCSA sets 0.04% federally, so it applies in every state. The reasoning is straightforward: an impaired driver behind the wheel of a loaded semi causes exponentially more damage than one in a sedan.

A first-time offense at 0.04% or above while driving a commercial vehicle results in a one-year CDL disqualification. Get caught twice and the disqualification is permanent. Many commercial carriers also enforce their own zero-tolerance policies and conduct random alcohol testing.

Enhanced Penalty Thresholds

Most states hit drivers with tougher penalties when BAC levels blow past the legal limit. These "aggravated DUI" or "extreme DUI" thresholds typically kick in between 0.15% and 0.20%, depending on the state.

The most common enhanced penalty threshold is 0.15%, used by roughly half the states. A handful use 0.16%, while New Jersey stands out with its strict 0.10% cutoff. Idaho, Massachusetts, and Tennessee set the bar higher at 0.20%.

Consequences get serious: mandatory minimum jail sentences (even for first-timers), extended license suspensions or revocations, heftier fines and court fees, mandatory ignition interlock device installation, court-ordered alcohol treatment programs, and felony charges in some jurisdictions.

Implied Consent Laws

All 50 states have implied consent laws — by driving on public roads, you automatically agree to chemical testing for alcohol or drugs if lawfully arrested for DUI. This is not the same as roadside consent; implied consent kicks in only after a formal arrest, not during an initial traffic stop.

Refusing a chemical test (breath, blood, or urine) stacks extra penalties on top of whatever DUI charges you face. In most states, refusal triggers automatic license suspension — usually 6 months to 1 year for a first refusal, longer for repeat refusals. Some courts will even use the refusal as evidence against you in proceedings.

Colorado frames it as "express consent" rather than "implied consent," but the practical consequences stay the same. Several state courts have ruled that warrantless blood draws violate the Fourth Amendment, pushing back on implied consent arguments. Breath tests, however, remain permissible under implied consent in all 50 states.