If a court has ordered an ignition interlock device on your vehicle after a DUI, you can expect to keep the breathalyzer in your car for anywhere from six months to three years in most cases, with repeat offenses pushing that period out to five, six, or ten years, and lifetime installation possible in a handful of states after a fourth conviction. The exact length depends on how many prior DUIs you have, your blood alcohol level at arrest, and the state that convicted you. Every state has an interlock law, and 31 states plus the District of Columbia require the device even for first-time offenders.1NCSL. State Ignition Interlock Laws
How Long by Offense Level
The number of DUI convictions on your record is the single biggest factor in how long the device stays in your car. Each state sets its own timelines, but the ranges below reflect the pattern across jurisdictions.1NCSL. State Ignition Interlock Laws
First Offense
Six months to one year is the most common range. Kentucky and the District of Columbia start at six months. Hawaii, New Mexico, and Oregon require a full year. A few states allow periods as short as 150 days for offenders who complete other requirements early.
Second Offense
One to three years in most states. Florida mandates at least one year. Connecticut requires three years. Washington goes up to five. The jump from a first to a second offense is where the length increases sharply.
Third Offense
Two to six years is typical. Alabama requires three years, Tennessee six, and Washington can impose ten. At this level, many states also layer on longer license suspensions and mandatory treatment programs that run alongside the interlock period.
Fourth or Subsequent Offense
A few states, including New Mexico, South Carolina, and Wyoming, require lifetime installation. In New Mexico and Wyoming, you can petition a court for removal after five years of clean compliance, and every five years after that, but approval is not guaranteed.
These durations are minimums. Judges often have discretion to extend the requirement past the statutory floor.
What Can Add Time to Your Requirement
Two people convicted of the same offense can end up with very different interlock periods. A high blood alcohol concentration at arrest is one of the most common triggers for a longer requirement. Many states treat a BAC of 0.15% or above as an aggravating factor, bumping a first offense into a higher penalty tier. Arizona, for example, requires a full year of interlock use for a first offense at that level.1NCSL. State Ignition Interlock Laws
Other circumstances that can add time include having a minor in the vehicle at the time of the offense, causing an accident that injured someone, or refusing a chemical test at the traffic stop. Court-ordered probation terms can set the interlock period longer than the statutory minimum. And once the device is installed, any violation while you’re using it usually extends the requirement or resets your compliance clock. That includes failed breath tests, missed rolling retests, missed calibration appointments, and any sign the device has been tampered with. Every event is logged and downloaded at each service visit, so violations do not go unnoticed.
When the Clock Actually Starts
In several states, the interlock period doesn’t begin until your license suspension ends. That means the total time the device sits in your car can be months longer than the statutory number suggests. Check with your court or DMV about how your state sequences the two penalties before you count from your conviction date.
Medical Exemptions
If you have a chronic respiratory condition such as severe asthma or COPD, you may not be able to produce enough breath volume to operate the device. Many states allow a medical exemption, though the process usually requires documentation from a licensed healthcare provider and approval from the court or DMV. Not every state offers this option, and the exemption does not erase the DUI consequences. It typically means alternative monitoring or driving restrictions in place of the interlock.
Early Removal
Some states allow you to petition for early removal if you’ve maintained a spotless compliance record for a minimum period, typically at least half of your required installation time. The bar is high: zero failed tests, no missed retests, no tampering flags, and completion of any court-ordered programs like alcohol education or substance abuse treatment. Even with a perfect record, early removal is not automatic. You’ll need to file a formal request with the court or DMV, and a judge has to approve it.
A handful of states run structured step-down programs where good compliance during the first portion of your interlock period automatically qualifies you for a shorter total requirement. In most places, though, the process involves a hearing where you demonstrate that you’ve met every condition. Any violation during the compliance window usually disqualifies you and may restart the waiting period.
Removing the Device When Your Time Is Up
Once your interlock period officially ends, removal follows a specific sequence, and skipping a step can delay reinstatement of your full driving privileges.
- Confirm eligibility with the court, DMV, or your probation officer. Do not schedule removal until you have written or electronic confirmation that your period is complete and all conditions are satisfied.
- Schedule removal with the same company that installed the device. A certified technician handles the work, restoring your vehicle’s wiring and ignition to its original condition.
- Allow the provider to pull the final data download and submit a completion report to the court or DMV confirming that the device has been removed and your obligation is fulfilled.
- Visit the DMV if your state requires it, to have the interlock restriction officially removed from your license, pay any reinstatement fee, and obtain a new license without the restriction code.
One trap to avoid: your SR-22 high-risk insurance requirement, if your state imposed one alongside the DUI, often outlasts the interlock period by a year or more. Dropping that coverage as soon as the device comes off can trigger an automatic license suspension even after the interlock is gone. Confirm your SR-22 end date separately before you cancel anything.