Arizona requires a certified ignition interlock device for 12 months after a first DUI conviction under A.R.S. § 28-3319(D)(1)(a), and subsection (H) of the same statute directs the Motor Vehicle Division to defer the remainder of that period once a driver satisfies six listed conditions.
James Novak handles first-offense DUI sentencing and interlock compliance for drivers in Tempe, Mesa, and the surrounding Maricopa County courts.
James Novak has spent more than 20 years defending DUI charges across Maricopa County, first as a prosecutor for the State and now on the defense side. I tell first-offense clients the same thing early in a case: the jail exposure is usually the smallest part of a first DUI sentence, and the ignition interlock device is the part they will live with every morning for a year. It affects how they get to work, who can borrow the car, and what happens in a parking lot when the device asks for a rolling retest.
Arizona law contains a provision that can end that year at the halfway point, and a large number of drivers serve all 12 months without ever learning it exists. In my office the interlock terms get litigated at sentencing, alongside the jail number and the fines that make up the rest of the DUI charges and penalties a first offense carries.
An ignition interlock deferment is a statutory mechanism that stops the interlock requirement before its full term runs. Under A.R.S. § 28-3319(D)(1)(a), the Motor Vehicle Division imposes a 12-month interlock requirement on receipt of a report of conviction for a first DUI. Subsection (H) of the same statute then directs the department to defer whatever remains of that period once six conditions are satisfied.
The verb in A.R.S. § 28-3319(H) carries real weight for a driver deciding whether this is worth pursuing. The statute states that the department “shall defer the remainder of the time period,” which is a command rather than a grant of discretion. The Motor Vehicle Division is not weighing whether a driver deserves relief, and there is no hearing at which sympathy matters. Each of the six conditions is either documented or it is not. Eligibility is therefore built during the interlock period rather than argued at the end of it, and several of the conditions can be lost through inattention months before anyone applies.
The conditions appear as a numbered list in A.R.S. § 28-3319(H), and all six must apply. They divide cleanly into facts fixed at sentencing, which a driver cannot change afterward, and facts built during the interlock period, which a driver controls.
| Condition | What A.R.S. § 28-3319(H) requires | When it is decided |
|---|---|---|
| Sentencing provision | The person is sentenced pursuant to A.R.S. § 28-1381, subsection I | At sentencing |
| Alcohol education | Successful completion of an alcohol education program of at least 16 hours | During the period |
| Device compliance | A functioning device maintained on all vehicles the person operates, and the department’s device requirements met | During the period |
| Start attempts | Fewer than two attempts to operate at an alcohol concentration of 0.08 or more during the period of license restriction or limitation | During the period |
| Accident at the offense | At the time of the offense, no motor vehicle accident resulting in physical injury or property damage | At the offense |
| Reporting | All necessary compliance information provided to the department by the device provider, the screening program, and the education program | During the period |
Two of the six are settled before the interlock is ever installed. The sentencing condition and the accident condition are decided by the charge a driver is convicted of and by what happened on the night of the arrest, which is why the deferment belongs in a plea discussion rather than a compliance conversation a year later. A first-offense case resolved under § 28-1381 preserves the deferment, and a case resolved under a different sentencing provision does not.
Subsection (H) sets the deferment to commence at the later of six months from the date the interlock was installed or the completion of the subsection’s requirements. Six months functions as a floor rather than a date, so a driver who finishes the 16-hour program in month nine starts the deferment in month nine and gives away three months to scheduling.
The start of the underlying 12-month period is governed separately by A.R.S. § 28-3319(F), which ties it to the date the driver completes the required screening, education, or treatment and is otherwise eligible to reinstate driving privileges. That subsection also credits time already served on a device installed under a special ignition interlock restricted driver license. Drivers commonly assume the clock began at conviction or at installation, and the gap between that assumption and the statute’s actual trigger can run several months in either direction. Every later deadline depends on which date is correct.
A.R.S. § 28-3319(I) then makes the deferment permanent, subject to one condition. If the driver is arrested for a violation of § 28-1381, § 28-1382, or A.R.S. § 28-1383 that occurs during the deferment period, the department revokes the deferment and requires the remainder of the original 12 months. The statute keys that consequence to the arrest and to the date the offense occurs, not to a conviction, so a driver whose new case is later dismissed may still have lost the deferment in the meantime.
I have handled first-offense DUI matters in the Tempe, Mesa, Chandler, and Scottsdale courts for more than two decades, and my engineering background shapes how I read the device data that decides most of these questions. If you want the deferment argued as part of your sentence rather than handled as an afterthought, the Arizona DUI defense section of this site sets out where it fits in a first-offense case.
An interlock deferment turns almost entirely on records, and the records are generated automatically by machines and program administrators rather than by testimony. Four categories decide it. The certified device’s own datalog is the central one, because it records every start attempt, every reading, every rolling retest, and every service visit, and the provider transmits that data to the Motor Vehicle Division on a schedule.
The datalog is where the condition in § 28-3319(H)(4) is won or lost, and it is also where drivers are most often surprised. A device records an elevated reading without regard to its cause, and mouthwash, certain medications, and residual mouth alcohol can all produce one. What the statute counts is attempts at 0.08 or more, twice or more, during the period of restriction, so a driver disputing eligibility is usually disputing what a specific recorded event actually measured rather than whether the event occurred.
The remaining three categories are documentary. The alcohol education program’s completion certificate has to show at least 16 hours and has to reach the department through the program rather than through the driver. The screening program’s compliance report is a separate transmission with its own failure modes. The police report and any accident report from the night of the arrest decide the condition in § 28-3319(H)(5), and whether a low-speed contact with no injury was written up as property damage can settle eligibility on its own. From the department’s side of the file, a gap in any of these transmissions looks identical to noncompliance.
I raise the deferment during plea negotiations, not after sentencing. The first condition in the statute is a sentencing condition, so the moment a case resolves under a provision other than § 28-1381(I), the deferment is gone regardless of how carefully the driver complies for the next year. That single fact reorders how I value competing offers on a first-offense case, and it is a reason a marginally better jail number is sometimes the worse deal.
My engineering degree does steady work on the device side of these cases. I read interlock datalogs the way I read breath instrument calibration and maintenance records, looking at what the device actually measured, when it was last serviced, and whether a recorded event is consistent with the rest of the log. A driver facing a claim of two disqualifying start attempts is facing a technical assertion, and it can be examined.
I also track the interlock period against the 84-month window that governs sentencing on any later charge, because the two intersect more often than clients expect. A new arrest inside the deferment revokes it under § 28-3319(I), and the same conduct can also move a later case into repeat offender DUI territory, where a second violation within 84 months carries a minimum of 90 days in jail under § 28-1381(K), of which the court may suspend all but 30 under § 28-1381(L) if the driver completes the ordered screening or treatment program. Arizona measures that window by the dates the offenses were committed rather than the order of the convictions, so the sequence a client remembers is often not the sequence that counts.
The conditions that a driver controls are all lost the same way, through delay and through assuming someone else is transmitting a document. Practical steps for anyone currently on an Arizona interlock:
No. The first condition in A.R.S. § 28-3319(H) is that the person was sentenced pursuant to A.R.S. § 28-1381, subsection I, which is the sentencing provision for a first violation of the basic DUI statute. A conviction for extreme DUI is sentenced under A.R.S. § 28-1382, subsection D, so it does not satisfy that condition. A driver facing an extreme DUI charge who wants any access to the deferment has to change the conviction itself, not the interlock terms that follow it.
No. The condition in A.R.S. § 28-3319(H)(4) is that the person has not attempted to operate a vehicle with an alcohol concentration of 0.08 or more two or more times during the period of license restriction or limitation. The statute sets the threshold at two attempts, so a single recorded attempt above 0.08 does not by itself end eligibility. The device records every start attempt, and the provider reports that data to the Motor Vehicle Division.
A.R.S. § 28-3319(I) makes the deferment permanent unless the person is arrested for a violation of A.R.S. § 28-1381, 28-1382, or 28-1383 that occurs during the deferment period. If that arrest happens, the department revokes the deferment and requires the driver to complete the remainder of the original 12-month period. The trigger is the arrest date falling inside the deferment window, not the eventual outcome of the new case.
The condition in A.R.S. § 28-3319(H)(5) is narrower than it first reads. It asks whether, at the time of the offense, the person was involved in a motor vehicle accident that resulted in physical injury or property damage. An accident occurring later during the interlock period is not what this condition measures, and an incident with no injury and no property damage does not meet its terms either.
The reporting duty does not sit with the driver. A.R.S. § 28-3319(H)(6) requires that all necessary compliance information be provided to the department by the ignition interlock device provider, the alcohol screening program, and the alcohol education program. A driver who has personally done everything the statute asks can still stall on a report that one of those three never transmitted, which is why confirming receipt is worth doing directly.
If you are facing a first DUI in Maricopa County, the interlock terms are decided by how the case resolves, and that window closes at sentencing. As a former Maricopa County prosecutor with more than 20 years defending Arizona DUI charges, I know how the State builds these cases and where the sentencing provisions leave room. Call my office at (480) 413-1499 for a free initial consultation, available 24 hours a day, or reach me through the Tempe DUI defense contact page.