Arizona requires an ignition interlock device on every vehicle you operate after any DUI conviction under ARS 28-3319. The mandatory interlock period ranges from 12 months for a standard first-offense DUI to 24 months for felony Aggravated DUI, with monthly costs between $60 and $80 for monitoring plus $70 to $150 for installation. Call Oliverson Law DUI & Criminal Defense at (480) 582-3637 to discuss your interlock requirements.
ARS 28-3319: Arizona’s Mandatory Interlock Statute
Arizona Revised Statutes Section 28-3319 mandates that every person convicted of a DUI offense install a certified ignition interlock device on each motor vehicle they operate. Unlike some states that impose interlock requirements only for repeat offenders or high-BAC convictions, Arizona applies this mandate across every DUI classification, including first-offense standard DUI under ARS 28-1381. The requirement took its current form through legislative amendments designed to reduce repeat DUI incidents, and Arizona’s approach is among the most comprehensive in the country.
The requirement is conviction-triggered, not discretionary. Judges in Maricopa County municipal courts, justice courts, and Superior Court do not have authority to waive the interlock requirement for convicted DUI offenders. Once a guilty plea is entered or a jury returns a guilty verdict on any DUI charge, the interlock order is mandatory. This applies equally whether the case is resolved in Tempe Municipal Court for a first-offense misdemeanor or in Maricopa County Superior Court for a felony Aggravated DUI under ARS 28-1383.
The device must be installed on every vehicle you operate. ARS 28-3319 does not limit the interlock to your primary vehicle. If you own, lease, or regularly drive multiple vehicles, each one must have an interlock installed and maintained during the entire mandatory period. Driving any vehicle without a functioning interlock while subject to the requirement constitutes a separate criminal offense, carrying additional penalties including extension of the interlock period and potential license revocation.
Interlock replaces full license suspension for restricted driving. Arizona’s interlock program functions as a conditional driving privilege. After serving any initial hard suspension period where no driving is permitted, the interlock allows you to resume driving with the restriction that every vehicle start requires a clean breath sample. Without agreeing to the interlock installation, you cannot obtain a restricted or reinstated license during the mandatory period, leaving you with no legal driving option until the full term expires.
| DUI Charge | Statute | Interlock Required | Court That Orders It |
|---|---|---|---|
| Standard DUI (1st offense) | ARS 28-1381 | Yes – 12 months | Municipal / Justice Court |
| Standard DUI (2nd within 84 mo.) | ARS 28-1381 | Yes – 12 months | Municipal / Justice Court |
| Extreme DUI (BAC 0.15+) | ARS 28-1382 | Yes – 18 months | Municipal / Justice Court |
| Super Extreme DUI (BAC 0.20+) | ARS 28-1382 | Yes – 18 months | Municipal / Justice Court |
| Aggravated DUI (felony) | ARS 28-1383 | Yes – 24 months | Maricopa County Superior Court |
Interlock Duration by Offense Level
The length of time you must maintain an ignition interlock device depends on the specific DUI statute under which you were convicted, whether the offense is a first or subsequent conviction within the 84-month lookback window, and whether additional aggravating factors apply. Arizona law sets minimum interlock periods for each tier, and courts cannot reduce them below the statutory floor.
Standard DUI under ARS 28-1381: 12 months. Both the “impaired to the slightest degree” prong and the 0.08 BAC per se prong carry a 12-month interlock requirement upon conviction. This applies to first offenses and second offenses alike, though a second offense within 84 months triggers longer license revocation and harsher jail time separately from the interlock period. The 12-month clock begins when the device is installed on your vehicle and verified by ADOT, not from the date of sentencing or conviction. Any gap between sentencing and installation does not count toward the required period.
Extreme and Super Extreme DUI under ARS 28-1382: 18 months. When your BAC test results show 0.15 or above (Extreme) or 0.20 or above (Super Extreme), the interlock period extends to 18 months. These cases typically involve blood draws processed through the Scottsdale Police Department crime lab, Mesa Police Department lab, or the Arizona Department of Public Safety lab. Defense challenges to BAC evidence through independent retesting or chain-of-custody objections can affect the ultimate charge level and, by extension, the interlock duration if the charge is reduced through negotiation or suppression.
Aggravated DUI under ARS 28-1383: 24 months. Felony Aggravated DUI convictions carry the longest interlock requirement at 24 months. Because Aggravated DUI often involves prison time through the Arizona Department of Corrections, the interlock period begins after release, not during incarceration. A person sentenced to four months in prison for a third DUI within 84 months would begin their 24-month interlock obligation only upon release and vehicle installation verification. The total time between arrest and completion of the interlock can extend well beyond three years when prison time, post-release supervision, and the interlock period run consecutively.
How the Ignition Interlock Device Works
An ignition interlock device is a breath alcohol testing unit wired into your vehicle’s ignition system. The device requires you to provide a breath sample before the engine will start and periodically while driving. Understanding the mechanics of how the device operates, what triggers a violation, and what consequences follow a failed test is critical for anyone subject to Arizona’s interlock requirement.
Initial Breath Sample to Start the Vehicle
Before the engine will turn over, you must blow into the handheld unit for approximately five seconds using a specific breath pattern (typically a hum-and-blow technique calibrated to prevent circumvention). If your breath alcohol concentration registers below the device’s preset threshold of 0.02 BAC, the interlock unlocks the ignition circuit and allows the engine to start. A reading at or above 0.02 triggers a lockout, preventing the vehicle from starting.
Rolling Retests While Driving
The device prompts random rolling retests at intervals between 5 and 30 minutes while the vehicle is in operation. You have approximately six minutes to provide the sample after the prompt. A failed rolling retest does not shut off the engine mid-drive for safety reasons. Instead, the device logs the violation, activates the horn in a repeating pattern, and flashes the headlights until you either provide a passing sample or turn off the vehicle. All rolling retest results are recorded in the device’s data log.
Monthly Calibration and Data Download
Arizona requires the device to be brought to a certified provider every 30 days for calibration verification and data download. The provider transmits all logged data to ADOT, including every start attempt, every rolling retest, any failed samples, any missed calibration appointments, and any evidence of tampering or circumvention. Missing a calibration appointment triggers an automatic lockout period and a violation report to the court.
Violation Reporting and Consequences
ADOT and the sentencing court receive reports of every violation event. Violations include failed startup tests, failed rolling retests, missed calibration appointments, evidence of tampering (disconnecting the device, using an air compressor to simulate breath), and driving a non-interlock vehicle. Consequences range from warning letters for isolated incidents to extension of the interlock period, revocation of the restricted driving privilege, or additional criminal charges for tampering under ARS 28-3319(H).
What the device measures and does not measure. The interlock detects ethyl alcohol in breath using a fuel cell sensor, the same technology used in preliminary breath testing devices carried by law enforcement. Mouthwash, certain medications, and fermented foods can produce false positive readings. Most devices include a brief waiting period and retest option to account for residual mouth alcohol. However, the device does not detect drugs, and it cannot distinguish between alcohol consumed recently and alcohol metabolized hours earlier. If you receive a false positive, you typically have two to three minutes to rinse and retest before the lockout engages.
Schedule a consultation to review your interlock compliance record, challenge reported violations, and prevent unnecessary extensions. Office: 60 E Rio Salado Pkwy, Suite 900, Tempe, AZ 85281.
Call (480) 582-3637Or request a free consultation online
Costs, Certified Providers, and Installation
The financial burden of an ignition interlock device extends across the entire mandatory period and includes several cost components beyond the initial installation. Arizona requires that all interlock devices be installed and serviced by ADOT-certified providers, and the defendant bears all costs. Courts do not subsidize or reimburse interlock expenses.
Installation costs range from $70 to $150. The exact amount depends on the certified provider, your vehicle make and model, and whether your vehicle requires additional wiring modifications. Vehicles with push-button ignition systems or advanced anti-theft electronics may incur higher installation fees due to the complexity of integrating the interlock into the existing electrical system. Installation appointments typically take 60 to 90 minutes, and the provider must verify the device is functioning correctly and transmitting data to ADOT before you leave.
Monthly monitoring and calibration fees run $60 to $80. This covers the monthly service appointment where the provider recalibrates the device sensors, downloads logged data for ADOT reporting, and inspects for signs of tampering or physical damage. Over a 12-month standard DUI interlock period, monitoring fees alone total $720 to $960. An 18-month Extreme DUI period runs $1,080 to $1,440, and a 24-month Aggravated DUI period costs $1,440 to $1,920 in monitoring fees.
Removal fees and additional charges. Most providers charge $50 to $100 for device removal at the end of the mandatory period. Additional fees apply for lockout resets caused by missed calibration appointments (typically $50 to $75 per reset), replacement of damaged or malfunctioning devices, and vehicle transfers if you change vehicles during the interlock period. Some providers also charge a monthly lease or rental fee for the device hardware separately from the monitoring service.
| Cost Component | Amount | Frequency | 12-Month Total |
|---|---|---|---|
| Installation | $70 – $150 | One-time | $70 – $150 |
| Monthly monitoring / calibration | $60 – $80 | Monthly | $720 – $960 |
| Device removal | $50 – $100 | One-time | $50 – $100 |
| Lockout reset (if needed) | $50 – $75 | Per incident | Varies |
| Estimated 12-month total | $840 – $1,210 |
ADOT-certified providers in Maricopa County. Arizona maintains a list of approved interlock providers through the Department of Transportation. Major certified providers operating in the Phoenix metropolitan area include Intoxalock, Smart Start, LifeSafer, and Draeger. Each provider has multiple installation locations across Maricopa County, including facilities near Tempe, Mesa, Chandler, Scottsdale, Gilbert, and Phoenix. Your attorney or the court can provide the current certified provider list, and you have the right to choose among any approved provider regardless of which one the court references.
Driving with the interlock vs. full suspension. Without interlock installation, you have no legal right to drive during the mandatory period. The interlock functions as the mechanism that converts a full license suspension or revocation into a restricted driving privilege. Once installed and verified by ADOT, you can drive any vehicle equipped with the device for any lawful purpose, including work, school, medical appointments, and personal errands. There is no restriction on driving hours or destinations while the interlock is active and compliant. This makes the interlock, despite its cost and inconvenience, substantially less disruptive than serving the full suspension period without driving privileges.
Why Clients Choose Oliverson Law for IID Issues
Ignition interlock issues intersect with DUI defense at multiple points, from challenging the underlying conviction that triggers the requirement to contesting violations reported during the interlock period. Oliverson Law DUI & Criminal Defense handles both sides of this equation across every court in Maricopa County, drawing on the firm’s combined experience in law enforcement, prosecution, and judicial decision-making.
Founding attorney Derek Oliverson processed DUI arrests as a police officer in Henderson, Nevada, where he observed firsthand how BAC evidence was collected and how interlock compliance was monitored post-conviction. He later prosecuted DUI cases in Mohave County, where he recommended interlock terms as part of sentencing packages. As a judge at Page Magistrate Court and Glendale City Court, he ruled on interlock violation hearings and decided whether to extend mandatory periods based on compliance data. That progression through every role in the criminal justice process gives the firm direct insight into how interlock violations are evaluated, what evidence courts rely on, and where the system’s reporting can be challenged.
Attorney David Tangren brings felony prosecution experience from the Pima County Attorney’s Office, where he handled cases involving repeat DUI offenders subject to extended interlock periods following Aggravated DUI convictions. His understanding of how prosecutors use interlock violation data to support enhanced sentencing on new charges directly informs the firm’s defense approach for clients facing compliance disputes. Together, the team has handled over 5,000 cases and maintains a 4.9/5 rating from more than 150 client reviews.
Whether your case involves negotiating charge reductions that shorten the interlock period, defending against reported violations caused by device malfunctions or false positives, or navigating the ADOT reinstatement process after completing your interlock term, Oliverson Law provides guidance grounded in statutory specifics and courtroom experience. The firm handles DUI defense, Extreme DUI cases, and Aggravated DUI defense across Tempe Municipal Court, Phoenix Municipal Court, Scottsdale City Court, and Maricopa County Superior Court.
Frequently Asked Questions
The mandatory interlock period depends on your conviction level. A standard first-offense DUI under ARS 28-1381 requires 12 months of interlock use. Extreme DUI under ARS 28-1382 with a BAC of 0.15 or above requires 18 months. Super Extreme DUI at 0.20 BAC or above also requires 18 months. Aggravated DUI under ARS 28-1383, charged as a felony, requires 24 months after release from prison. Second offenses within 84 months add additional time to each tier.
Installation costs range from $70 to $150 depending on the certified provider and your vehicle type. Monthly monitoring and calibration fees run $60 to $80 per month. Over a 12-month interlock period for a standard DUI, total costs typically reach $840 to $1,210. Longer periods for Extreme or Aggravated DUI increase the total proportionally. Some providers charge additional fees for missed calibration appointments, lockout resets, or early removal requests that the court has not authorized.
A failed rolling retest does not shut off the engine while you are driving. The device logs the failed sample, triggers visual and audible alerts, and activates the horn in a repeating pattern until you either provide a clean sample or pull over and turn off the vehicle. The failed retest is recorded and reported to ADOT and the court. Repeated failures or patterns suggesting attempted circumvention can result in an interlock violation hearing, extension of the interlock period, or revocation of your restricted driving privilege.
No. Arizona law requires the interlock device on every vehicle you operate during the mandatory period. Driving any vehicle that does not have an installed and functioning interlock device is a separate criminal offense under ARS 28-3319. If you are caught driving without the interlock, you face additional charges, extension of your interlock requirement period, and potential license revocation. Employer-owned vehicles may qualify for a limited exemption if your employer provides written authorization and the vehicle is used strictly for work purposes.
Yes. A set-aside under ARS 13-905 does not eliminate or shorten the ignition interlock requirement. The set-aside modifies your criminal record notation but explicitly does not affect penalties and restrictions imposed by the Arizona Department of Transportation, including the interlock mandate under ARS 28-3319. You must complete the full interlock period ordered by the court regardless of whether the underlying conviction is later set aside. The interlock obligation runs independently from the criminal record status of your case.
Speak directly with an attorney who has served as a police officer, prosecutor, and judge. Office: 60 E Rio Salado Pkwy, Suite 900, Tempe, AZ 85281.
Call (480) 582-3637Or request a free consultation online