Locations
Where to install an ignition interlock, state by state
Interlock rules are written state by state — the term you serve, the breath threshold, and which providers are approved all change at the state line. We track 10,531 certified centers across 51 states and DC. Start with yours.
| State | Certified centers | Cities covered | Provider networks | First offence | What the state publishes |
|---|---|---|---|---|---|
| California | 1,073 | 396 | 8 | None for a first non-injury offense; 1 year if it caused injury; with one prior, 1 year (2 with injury); with two, 2 years (3 with injury); with three or more, 3 years | Nothing published |
| Texas | 1,005 | 324 | 7 | For the duration of the suspension, unless the court finds good cause to remove the device early | Nothing published |
| Florida | 829 | 229 | 8 | Court discretion on a plain first conviction; at least 6 months at 0.15% or with a minor in the car. Second conviction 1 year (2 years at 0.15%), third 2 years, fourth or more 5 years | Nothing published |
| Pennsylvania | 638 | 371 | 7 | None for a first general-impairment offense; required at high BAC, on a refusal, or on a repeat, with the Ignition Interlock Limited License as the route back to driving | Nothing published |
| Illinois | 465 | 228 | 7 | For the length of the statutory summary suspension; the Secretary of State downloads the device data every 30 to 60 days and asks you to explain any violation it finds | Publishes about $110 a month |
| New York | 418 | 246 | 4 | Normally at least 12 months on a DWI sentence, and required of anyone sentenced since 15 August 2010; you have 10 days after sentencing to fit it | Publishes about $100 a month |
| Arizona | 346 | 88 | 6 | At least 12 months on a standard first conviction; longer at higher readings — 12 months for Extreme DUI at 0.15%, 18 months for Super Extreme at 0.20% (A.R.S. 28-1382) | Nothing published |
| Maryland | 336 | 129 | 7 | Set on referral by the MVA, a court or an administrative law judge; a repeat offender within five years faces a year of suspension or a year in the program, then a further restricted year | Publishes about $70 a month |
| Wisconsin | 336 | 195 | 5 | Minimum 12 months, counted from the day a license is issued — ordered only at 0.15% BAC or higher, or on refusal | Nothing published |
| Missouri | 310 | 144 | 6 | 90 days on an immediate restricted privilege with the device (request within 15 days of the notice), against a 30-day suspension plus 60-day restricted privilege without it | Nothing published |
| Minnesota | 305 | 184 | 6 | Optional for a first offense; mandatory on a second or later alcohol or drug offense within 20 years (10 years for incidents before 1 July 2025). Drivers canceled as inimical to public safety serve 3–6 years | Nothing published |
| Colorado | 286 | 79 | 4 | 9 months for a first offense below 0.149% (running alongside the revocation); 2 years at 0.15% or higher, and 2 years automatically for refusing the test | Nothing published |
| Arkansas | 231 | 99 | 6 | A period equal to the driving license suspension, with the restriction lasting until that period is complete | Nothing published |
| Iowa | 231 | 152 | 5 | For the length of the temporary restricted license on a first OWI; with two or more offenses, at least 365 days from the date you receive the license or the length of it, whichever ends later | Nothing published |
| Kansas | 230 | 104 | 5 | Below 0.15% BAC a first occurrence is a 30-day suspension followed by six months or a year restricted to the device; at 0.15% or above it is a year of suspension followed by a year on the device | Nothing published |
| Nebraska | 186 | 76 | 7 | Set by the revocation you waive the hearing on; you must serve any required wait period first, and the permit needs a certificate of installation for every vehicle you will drive | Nothing published |
| Tennessee | 183 | 97 | 5 | Set by the court order for a restricted license (form ORDL signed by the judge), which the provider uses to calculate your time in the program | Caps the monthly fee at $125 |
| Louisiana | 180 | 96 | 5 | Matched to the suspension the device buys you out of; the OMV handles reinstatement and holds the record of the requirement | Nothing published |
| Ohio | 180 | 121 | 5 | For the period of the license suspension, which the court may cut by up to half when it grants unlimited driving privileges with a certified device (ORC 4510.022(C)(2)(b)) | Nothing published |
| Connecticut | 178 | 93 | 7 | Required to reinstate after any alcohol-related suspension; the clock starts on the day your license is restored, not the day the device is fitted | Nothing published |
| Indiana | 175 | 104 | 6 | Set by the court as a condition of specialized driving privileges; the installation period is credited against the suspension | Nothing published |
| New Jersey | 175 | 114 | 7 | 3 months at 0.08–0.10% BAC; 7–12 months at 0.10–0.15%; 12–15 months at 0.15% or higher | Nothing published |
| Michigan | 171 | 117 | 5 | Set through the Secretary of State hearing process as a condition of the restricted license, not fixed as a single term by MCL 257.319 | Nothing published |
| Massachusetts | 158 | 106 | 5 | For the whole hardship license period; multiple-OUI offenders keep the device a further two years after full reinstatement. Since 1 July 2021 certain first offenders seeking a hardship license need one too | Nothing published |
| Washington | 152 | 71 | 5 | For the remainder of the suspension, revocation or denial — you may apply at any point, including immediately after arrest | Publishes about $150 a month |
| North Carolina | 145 | 54 | 3 | 1 year from restoration if the revocation was a year; 3 years if it was four; 7 years after a permanent revocation | Nothing published |
| Oklahoma | 142 | 69 | 8 | 180 active interlock days for a first revocation, 365 for a second, 730 for a third or later — and the last 90 days of each must be violation-free | Publishes about $99.99 a month |
| Kentucky | 139 | 84 | 6 | Suspension drops from 6 months to 4 if you clear 90 consecutive violation-free days on the device; second offense 18 months down to 12 (120 clean days), third 36 to 18, fourth 60 to 30 | Nothing published |
| Nevada | 123 | 22 | 7 | 185 days for a first conviction below 0.18% BAC; 12 to 36 months at 0.18% or above; one year for a second conviction within 7 years, three years for a felony | Nothing published |
| Georgia | 116 | 77 | 4 | Set by the permit rules: a second DUI within five years requires the interlock permit under O.C.G.A. 40-5-63(a)(2), and anyone excused from the device on financial hardship grounds gets no limited permit until the required period is served | Caps the monthly fee at $75 |
| Oregon | 106 | 45 | 5 | Set by ORS 813.602 for the underlying suspension; the hardship permit runs alongside it and requires the device on any vehicle you drive | Nothing published |
| Idaho | 95 | 44 | 6 | Tied to the administrative license suspension; ITD collects the reinstatement fee and issues the restricted driving permit that the device makes possible | Nothing published |
| South Carolina | 95 | 53 | 4 | Set by the offense under the All Offender Law; drivers who decline to enroll simply stay suspended indefinitely rather than serving a fixed term | Nothing published |
| New Mexico | 76 | 28 | 8 | Required after every DWI conviction, first offense included; the MVD states there is no route around it | Publishes about $60 a month |
| New Hampshire | 75 | 55 | 4 | Ordered by a New Hampshire court or by the Commissioner of Safety under RSA 265-A:36; you may only drive vehicles fitted with a NH-approved device | Nothing published |
| Alaska | 74 | 29 | 7 | Set by the court at sentencing: it must order a device, the length depends on how many previous DUI or refusal convictions you have, and the court may exceed the statutory minimum at its discretion | Nothing published |
| Virginia | 73 | 40 | 3 | Not less than 12 consecutive months without an alcohol-related violation of the interlock requirements, and no longer than the period of suspension and restriction | Caps the monthly fee at $95 |
| Mississippi | 67 | 48 | 4 | Set by the court order for an interlock-restricted license, which is what avoids the administrative suspension in the first place | Nothing published |
| Maine | 65 | 53 | 4 | Reinstatement after 30 days of a 150-day suspension, with the device for the remaining term; a second offense reinstates after 9 months of three years, a third after 3 years of six | Nothing published |
| Utah | 55 | 36 | 6 | 18 months if you were 21 or older at arrest, 3 years if under 21; the Division states that subsequent offenses carry longer restriction periods | Nothing published |
| Vermont | 55 | 41 | 6 | For the balance of the suspension as a conditional reinstatement; the license renews annually until you are eligible for an unrestricted one | Nothing published |
| Rhode Island | 54 | 30 | 4 | Granted by the sentencing court under RIGL 31-27-2.8(b)(7) together with a hardship license; you must report the order to the DMV Adjudication Office at once so the restriction is added | Nothing published |
| Montana | 51 | 31 | 4 | For the probationary period set by the court. The underlying suspension is 6 months for a first DUI conviction or a first refusal, and a year for a second or subsequent within 10 years | Nothing published |
| Wyoming | 47 | 26 | 5 | Required on a first conviction only at 0.15% BAC or above, and on any second or subsequent conviction whatever the reading; the clock does not start until the interlock license is issued, however long the device has been fitted | Nothing published |
| Alabama | 36 | 27 | 4 | 90 days below 0.15% BAC (which cancels the 90-day suspension); 1 year at 0.15% or above, on a refusal, with a child under 14 in the car, or where someone was injured | Nothing published |
| West Virginia | 22 | 15 | 2 | Set by the Test and Lock Program; you must have the device fitted within six months of applying, and complete the program before full privileges are restored | Nothing published |
| Hawaii | 13 | 10 | 2 | Ordered for the revocation period; Hawaii DOT states the device must be fitted on any vehicle you operate and maintained at your own expense | Nothing published |
| South Dakota | 11 | 8 | 1 | Set by the court or supervising agency; the interlock is ordered case by case rather than by a fixed statutory term | Nothing published |
| North Dakota | 9 | 7 | 3 | A first offense carries a 91-day suspension below 0.18% BAC, or 180 days at 0.18% and above; the 360 days of 24/7 Sobriety Program participation start with a second offense within seven years | Nothing published |
| Delaware | 8 | 6 | 3 | Set by the program you enter: Delaware runs a First Offense Election diversion with the device and a separate voluntary program, and the license is not issued until you meet the minimum qualifications | Caps the monthly fee at $75 |
| District of Columbia | 2 | 1 | 3 | Set by the program enrollment period, which the DMV extends if you break the program rules or pick up another driving violation | Nothing published |