Pennsylvania's three tiers — and when a DUI becomes a felony
Pennsylvania grades alcohol DUIs by blood alcohol concentration: general impairment (.08 to .099), high rate (.10 to .159), and highest rate (.16 and above). Drug-based DUIs and most refusal cases are penalized at the highest tier. The penalties escalate sharply — a first offense runs from probation and a $300 fine at the lowest tier to a 72-hour mandatory minimum and a $1,000-plus fine at the highest — and prior offenses within a ten-year lookback multiply everything: mandatory minimums, fines, suspension lengths, and grading.
A DUI becomes a third-degree felony on a third offense within ten years at the highest tier or involving drugs, and on any fourth offense. Under Deana's Law, a fourth or subsequent highest-tier or drug DUI is a second-degree felony carrying up to ten years. Separate felony statutes apply when impaired driving causes serious injury or death.
In 2025, the Pennsylvania Supreme Court held in Commonwealth v. Shifflett that a prior ARD acceptance cannot be treated as a prior conviction for mandatory-minimum purposes, and the legislature responded with Act 58 of 2025, which created a distinct offense for a DUI committed within ten years after completing ARD, carrying second-offense-level mandatory minimums. How a prior ARD is treated is now one of the first questions in any repeat-DUI case, and getting it right can change the mandatory minimum a client faces.
The license is a separate case
The criminal case and the driver's license run on separate tracks with separate deadlines — and winning one does not decide the other. A chemical-test refusal triggers an automatic civil suspension from PennDOT of 12 or 18 months that stands even if the DUI charge is dismissed, and it must be appealed within 30 days of the notice's mailing date. Conviction suspensions run 12 or 18 months depending on the tier and priors, though a first-offense general-impairment conviction carries no suspension at all.
Most first offenders can apply for an ignition interlock limited license immediately rather than sitting out a hard suspension, and time on the interlock license counts toward any required interlock period. Commercial drivers face a harsher reality: a DUI in a personal vehicle still disqualifies a CDL for a year, ARD counts as a conviction against a CDL, and no limited license restores commercial driving — which makes early, CDL-aware strategy essential for anyone who drives for a living.
Where DUI cases are defended
DUI prosecutions are built on technical evidence, and technical evidence has rules. The BAC generally must be established within two hours of driving — late blood draws need statutory justification. After Birchfield v. North Dakota, a warrantless blood draw requires valid consent given after accurate warnings, and every blood case gets checked for the warrant, the consent, and the exact form the officer read. Breath results have their own regulatory checklist: Pennsylvania requires two consecutive breath tests using the lower result, a simulator test, and an accuracy inspection within 30 days before evidentiary use — and if the two breath results differ by .02 or more, the results are disregarded and the device comes out of service. Calibration and accuracy records are discoverable, and they are among the first documents requested here in every breath case.
Field sobriety testing has limits too: the standard battery is admissible as observation, but the eye-movement test requires expert foundation Pennsylvania courts do not presume. And in marijuana cases, metabolites remain detectable long after any impairment has passed — an issue that matters for the growing number of medical marijuana patients charged at the highest tier without evidence of actual impairment.
First offenders in every county in this practice have access to ARD, and each District Attorney sets its own admission policy — Chester County and Philadelphia publish detailed criteria, while Bucks, Delaware, and Montgomery counties evaluate applications case by case. A required CRN evaluation and alcohol highway safety school are part of the process everywhere. Whether ARD, a tier reduction, a suppression motion, or trial is the right path is exactly the kind of judgment a DUI case deserves before anything is signed.
