State data last reviewed October 1, 2026 · all 50 states
Ignition Interlock Requirements by State
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Ignition interlock rules differ across all 50 states: the trigger (any conviction, a high BAC, a refusal, a repeat offense), the length, and whether the court or the licensing agency orders it. The table below gives each state’s rule and its official source. Rules still being verified are marked with a dagger (15 states at the last review).
Keep reading for the full breakdownWhen an interlock is required, every state
Click a state for its interlock guide and the official program page.
| State | When it is required | Duration and how it is set | Official source |
|---|---|---|---|
| Alabama | Required for a first DUI at 0.15 or more, with a passenger under 14, after a refusal, or after a crash that injured someone, and for every repeat DUI. For a first DUI under 0.15 you may choose it to stay the suspension. | ALEA lists the interlock term by conviction: 90 days for a first offense under 0.15, 1 year for a first offense at 0.15 or more, 2 years for a second, 3 years for a third, and 4 years for a fourth or later. A refusal adds one year (except on a first conviction), and violations extend the term by six months. For a first offense under 0.15, the interlock is a voluntary way to stay the suspension. | Source 1: ALEA — Ignition Interlock LawsSource 2: ALEA — Hardship Driver License |
| Alaska | Required by the court after a DUI conviction involving alcohol and after a refusal conviction, starting when you get your license back. Also required for a limited license. The requirement is waived when you drive in a community on the state's list of places off the road system. | Minimums: 6 months after a first conviction, 12 months after a second, 18 months after a third, 24 months after a fourth, 30 months after a fifth, 36 months after a sixth or later, and 60 months after a felony. A limited license is available after 30 days on a first offense and 90 days on later ones, with interlock installed first. | Source 1: Alaska Statutes — AS 28.35.030, DUISource 2: Alaska Statutes — AS 28.35.032, Refusal to submit to chemical testSource 3: Alaska Statutes — AS 28.15.201, Limitation of driver's licenseSource 4: Alaska Court System — CR-483, Ignition Interlock Device Information SheetSource 5: Alaska DMV — Ignition Interlock InformationSource 6: Alaska DMV — Limited License |
| Arizona† | Required after any DUI conviction once your driving privilege is restored. A Special Ignition Interlock Restricted Driver License (SIIRDL) can also let you drive during a suspension. | At least 12 months for a standard DUI (may be reduced to 6 months in some cases), measured from when your privilege is eligible for reinstatement or MVD receives the conviction, whichever is later. Extreme, super extreme and aggravated DUI carry longer periods. | Source 1: ADOT MVD — Ignition Interlock FAQSource 2: A.R.S. §28-1381 — DUISource 3: A.R.S. §28-1382 — Extreme DUI |
| Arkansas | Required for DWI alcohol suspensions. You file a Confirmation of Interlock Requirement with Driver Control. | For a period equal to the license suspension. | Source 1: Arkansas DFA — DUI, DWI, BUI, BWI OffensesSource 2: Arkansas Department of Health — Ignition Interlock Device Regulations |
| California | Under the statewide ignition interlock program, a second or later DUI conviction requires an interlock to reinstate. For a first offense without injury, the court may order one for up to 6 months, or you may choose one to get a restricted license. | Without injury (Veh. Code §23152): 12 months with one prior within 10 years, 24 months with two, 36 months with three or more. With injury (§23153): 12 months with no priors, 24 with one, 36 with two. The term can be reduced by credit for time with an interlock during the APS suspension. The program runs through January 1, 2033. | Source 1: Cal. Veh. Code Div. 11.5, Ch. 2, Art. 5 — interlock and sentencing factorsSource 2: California DMV — DUI First Offenders, Alcohol, Non-InjurySource 3: California DMV — DUI Repeat Offenders, AlcoholSource 4: AB 366 (2025) — ignition interlock extension |
| Colorado | Required for Persistent Drunk Drivers: a BAC of 0.15 or more, a refusal, or two or more convictions. First offenders under 0.15 can use interlock to reinstate early. | At least 2 years for Persistent Drunk Drivers, and 2 to 5 years after a revocation for multiple DUI or DWAI convictions. A first-time offender who reinstates early keeps the interlock for the rest of the revocation. Drivers under 21 cannot apply for early reinstatement until the license has been revoked for one year. | Source 1: Colorado Revised Statutes 2024, Title 42Source 2: Colorado DMV — Reinstating After a DUI or Alcohol OffenseSource 3: Colorado DMV — Ignition Interlock ProgramSource 4: Colorado DMV — Early Reinstatement (Interlock) |
| Connecticut | Required after every administrative per se suspension and every DUI conviction, including first offenses and refusals. | Per se, age 21+: 6 months, 1 year, then 2 years for first, second, and third suspensions. Under 21 or refusal: 1, 2, then 3 years. Conviction: 1 year for a first, 3 years for a second, and lifetime (reviewable after 15 years) for a third. | Source 1: Connecticut OLR — Public Act Summary: An Act Concerning Ignition Interlock Devices (2014)Source 2: Connecticut OLR — Connecticut DUI Law (2016-R-0147) |
| Delaware | Mandatory for all DUI offenders, first and repeat, for offenses on or after February 1, 2015. First Offender Election participants can apply for an interlock license right away. | First offense: you can apply for an interlock license after 30 days of revocation (45 days if your BAC was 0.15 or more), and the device stays on for at least 12 months (17 months at 0.15–0.19, 23 months at 0.20 or more). First Offender Election: you can apply right away, and the device stays on for at least 4 months. Second offense: 16 to 28 months. Third: 21 to 33 months. Fourth or later: 54 months. The longer figures apply at higher BAC. | Source 1: 21 Del. C. §4177C — Ignition interlock licenses; reinstatementSource 2: Delaware DMV — Ignition InterlockSource 3: Delaware DMV — Driver Improvement FAQsSource 4: Delaware General Assembly — Session Laws Chapter 235 |
| Florida | Required for a first DUI with a BAC of 0.15 or more or a passenger under 18 in the vehicle, and for second and later convictions. For a first DUI at 0.08 or more, the court may order it. | At least 6 months for a first offense with 0.15+ or a passenger under 18 (2 years for a second such offense); otherwise at least 1 year for a second offense, 2 years for a third, and 5 years for a fourth or later. | Source 1: §316.193, Fla. Stat. — Online SunshineSource 2: §322.2715, Fla. Stat. — Online SunshineSource 3: FLHSMV — Florida DUI and Administrative Suspension Laws |
| Georgia | Required for a second or later DUI within 5 years, unless the court exempts you for financial hardship. After an ALS, you can choose an Ignition Interlock Device Limited Permit instead of a hearing. | 12 months for habitual violators once eligible to reinstate. DDS cannot issue an interlock permit until it has the 1205 form and the device is installed. | Source 1: Georgia DDS — Driver’s Manual, Chapter 1 ContinuedSource 2: Georgia DDS — Ignition Interlock Device Limited Permit Customer Information Sheet |
| Hawaii | The criminal sentence for a first or second OVUII includes installing an ignition interlock device. On the administrative side, you need an interlock and an Ignition Interlock Permit only if you want to drive during the revocation. | The interlock runs with the revocation period set in your Ignition Interlock Permit. Habitually OVUII requires an interlock in every vehicle you drive during a 3-to-5-year revocation. | Source 1: Hawaii DOT — Ignition Interlock FAQSource 2: Hawaii Judiciary — ADLRO Frequently Asked QuestionsSource 3: HRS §291E-61 — OVUIISource 4: HRS §291E-61.5 — Habitually OVUII |
| Idaho | On a first DUI, the court must require an interlock for 1 year after the suspension ends, unless it grants an exception. It is also required after a second or later DUI, after a refusal, and, according to ITD, after any ALS suspension unless the court waives it. | A period ending 1 year after the suspension ends, installed within 10 days after the absolute suspension period on a first DUI. After a second or later conviction, you may drive only a vehicle with a working interlock after the 1-year suspension. The device blocks starting at 0.025. | Source 1: Idaho Code §18-8002ASource 2: Idaho Code §18-8005Source 3: Idaho Code §18-8008Source 4: Idaho Transportation Department — Driver Records and Suspensions |
| Illinois† | A first offender can drive during the Statutory Summary Suspension only with a Monitoring Device Driving Permit (MDDP) and a Breath Alcohol Ignition Interlock Device (BAIID). Repeat offenders need a BAIID to get a Restricted Driving Permit after revocation. | The MDDP cannot take effect before the 31st day of the suspension and lasts for the rest of it. BAIID periods for repeat offenders are set by the Secretary of State when it grants relief. | Source 1: 625 ILCS 5/6-208.1 — Summary suspension periodsSource 2: Illinois Secretary of State — Reinstatement of Driving Privileges (BAIID)Source 3: Illinois Secretary of State — DUI Fact Book |
| Indiana | Not automatic. A court may require an ignition interlock as a condition of specialized driving privileges or probation. From July 1, 2026, interlocks may be ordered only when the OWI involved alcohol. | Time driving with an interlock as a condition of specialized driving privileges is credited toward the suspension. | Source 1: Indiana Office of Court Services — Driving PrivilegesSource 2: Indiana Courts Legislative Update — OWI penalties (SB 251 committee summary, 2026)Source 3: Indiana Criminal Justice Institute — Impaired Driving |
| Iowa | Required for any temporary restricted license (TRL) during an OWI revocation. After two or more OWI offenses, an interlock is also required once your license is reinstated. | For the life of the TRL. After two or more OWI offenses, 365 days on all vehicles you drive after reinstatement. | Source 1: Iowa DOT — Temporary Restricted License (TRL)Source 2: Iowa Code §321J.4 |
| Kansas | Required after the suspension period for test failures, refusals, and DUI convictions. The interlock must be approved by the Kansas Highway Patrol and paid for by you. | First test failure at 0.15 or more: 1 year. Second occurrence: 1 year. Third: 2 years. Refusals: 2 to 4 years. Proof of installation for the whole period is required before full reinstatement. | Source 1: K.S.A. 8-1014 Suspension and restriction of driving privilegesSource 2: Kansas Department of Revenue — Alcohol Actions Chart |
| Kentucky | Optional for most drivers through the Kentucky Ignition Interlock Program (KIIP). Choosing it shortens the suspension. The court may also require it during pretrial suspension. | You must stay violation-free for 90 consecutive days (first offense) or 120 consecutive days (second and later). Apply with form TC 94-175. | Source 1: Kentucky Transportation Cabinet — Kentucky Ignition Interlock ProgramSource 2: Kentucky Transportation Cabinet — DUI Penalties and ProgramsSource 3: Kentucky Revised Statutes 189A.070Source 4: Kentucky Revised Statutes 189A.200 |
| Louisiana† | Required on a first offense at 0.15 or more. After a refusal, OMV requires an interlock on reinstatement or with a hardship license when the arrest involved a crash with moderate or serious injury, a child 12 or younger in the vehicle, or a prior alcohol violation on your record. | On a first offense at 0.15 or more, the interlock is required for the first 12 months of the two-year suspension. OMV lists 365 days of interlock for a first refusal when interlock applies. | Source 1: La. R.S. 14:98.1 — First offense penaltiesSource 2: Louisiana OMV — Suspensions |
| Maine | Interlock is the path to early reinstatement. You petition the Secretary of State and get written approval before installing the device ($50 application fee). | First OUI: reinstate after 30 days of the 150-day suspension with interlock for the rest of the term. Second: after 9 months, interlock for 2 years. Third: after 3 years, interlock for 3 years. Fourth or more: after 4 years, interlock for 4 years. | Source 1: Maine BMV — Ignition Interlock Device InformationSource 2: 29-A M.R.S. §2508 — Ignition interlock device |
| Maryland | Under Noah’s Law, a DUI conviction, a DWI with a child under 16 in the car, and a test refusal require the Ignition Interlock Program. Since October 1, 2024, a probation before judgment for DUI or DWI also requires it. You can also elect it to keep driving during an MVA suspension. | 180 days for a BAC of 0.08 to under 0.15; 1 year for 0.15 or more or a refusal. Repeat offenses and court or MVA orders can require longer. | Source 1: Maryland MVA — Ignition Interlock ProgramSource 2: Maryland MVA — DR-15 Advice of RightsSource 3: Md. Code, Transp. §16-205.1 |
| Massachusetts | Under Melanie’s Law (c. 90 §24½), an interlock is required for anyone with two or more OUI convictions or alcohol-education assignments who gets a hardship license or has their license reinstated. | The device stays on for the whole hardship license period and for 2 years after full reinstatement for multiple offenders. | Source 1: Mass. RMV — Ignition Interlock Device ProgramSource 2: Mass. RMV — Melanie’s Law / IID Program documentSource 3: Mass. RMV — Multiple Offense OUI Hardship License Criteria |
| Michigan† | Required for a restricted license after 45 days of a High BAC suspension. Repeat offenders whose licenses are revoked usually need an interlock when the Secretary of State restores driving privileges after a hearing. | For High BAC, the interlock stays on for the rest of the 1-year suspension. After a revocation, interlock terms are set by the Office of Hearings and Administrative Oversight when it grants a restricted license. | Source 1: Michigan SOS — High BAC OffensesSource 2: Michigan SOS — License restoration hearings and interlock |
| Minnesota | Required for every repeat offender and for a first offense at 0.16 or more to regain driving privileges. First offenders under 0.16 can choose interlock instead of sitting out the 90-day revocation. | Under the 2025 law: 2 years with one prior in 20 years, 6 years for two, and 10 years for three or more. Program participants must also complete licensed substance use disorder treatment. | Source 1: MN DPS DVS — Ignition Interlock Device ProgramSource 2: MN House — New Laws 2025: DWI revocation and interlock changesSource 3: Laws of Minnesota 2025, chapter 29 |
| Mississippi | On a first alcohol DUI, you either install an interlock and hold an interlock-restricted license or serve a 120-day suspension. The court can order an interlock-restricted license instead of suspension on repeat offenses, and after a third offense only an interlock-restricted license is available once you are released. | The court sets the period for the interlock device (§63-11-31). A first-offense suspension is 120 days; after a third offense, only an interlock-restricted license is available for 3 years after release, and for 10 years after a fourth or later offense. | Source 1: Mississippi Legislature — SB 2305 (2023), nonadjudication, interlock and expunction textSource 2: Mississippi DPS — Frequently Asked Questions Related to Driving Under the Influence (2025)Source 3: Mississippi DPS Driver Service Bureau — DUI Department |
| Missouri | Required to reinstate if your record shows more than one alcohol- or drug-related enforcement contact, or on a first conviction with a BAC of 0.15 or more, or with injury or property damage. Also required for a restricted driving privilege after a refusal. | At least 6 months from the reinstatement date. Courts may order longer. | Source 1: Missouri DOR — Reinstatement RequirementsSource 2: Missouri DOR — Ignition Interlock Device FAQs |
| Montana | For a second or later DUI, the court orders the 24/7 sobriety program, an interlock if it recommends a probationary license, or forfeiture of the vehicle. Interlock is discretionary on a first offense. | The statute does not set a fixed interlock period. It is tied to a probationary license the court recommends. The 24/7 program centers on twice-daily breath testing about 12 hours apart. | Source 1: MCA 61-8-1010 — Ignition interlock; 24/7 sobriety and drug monitoring programSource 2: MCA 44-4-1203 — 24/7 sobriety and drug monitoring programSource 3: Montana DOJ — DUI Quick Reference Manual v1.1 |
| Nebraska† | Courts order an ignition interlock permit and device for the revocation period on DUI convictions. After an ALR revocation, you can apply for an interlock permit to drive. | On a first offense the interlock is required for the revocation period (6 months, 60 days on probation, 1 year at 0.15 or more). On a second offense there is a 45-day no-drive period, then an interlock for at least 1 year. For a third or later offense the court may order an interlock after a 45-day no-drive period. | Source 1: Neb. Rev. Stat. §60-6,197.03Source 2: Nebraska DMV — Ignition Interlock Permit |
| Nevada | A court must order it after any DUI conviction, including a first offense, with narrow exceptions (unable to give a deep lung breath sample, certified by a doctor, or living more than 100 miles from an interlock provider). It is also required to drive during the administrative revocation, under NRS 484C.210. | 185 days for a first offense, 1 year for a second within 7 years, and 3 years for a felony DUI or DUI causing death or substantial bodily harm. The clock starts when the DMV issues your ignition interlock privilege. The device must be installed within 14 days of the order. | Source 1: Nevada DMV — DUISource 2: NRS chapter 484C — Driving Under the InfluenceSource 3: NRS chapter 483 — Drivers’ Licenses |
| New Hampshire | Required by the court for an aggravated DWI or a second or later DWI. | At least 12 months and up to 2 years, starting after the revocation ends, in any vehicle you drive regularly. You pay for it, and proof of installation is required before your license is restored. | Source: RSA 265-A:36 — Alcohol Ignition Interlock Program |
| New Jersey | Required for nearly every DWI and refusal conviction under the 2019 law, including first offenses at 0.08 to under 0.10. You may not drive until the device is installed. | First offense: 3 months (0.08 to under 0.10); 7 to 12 months (0.10 to under 0.15); during the forfeiture and 12 to 15 months after (0.15 or more). A first refusal: during the forfeiture and 9 to 15 months after. Second or later offense or refusal: during the forfeiture and 2 to 4 years after. You may install an interlock after arrest and before conviction. For a 0.15 or more first offense, a second, or a third, an early-installed interlock earns 1 day of credit against forfeiture for every 2 days installed, except when the violation caused serious bodily injury. The interlock law runs until January 1, 2029. | Source 1: NJ Courts — Notice on the December 2019 DWI lawSource 2: NJ Courts — Administrative Directive #04-24 (interlock law)Source 3: P.L. 2023, c. 191 — Interlock, plea agreement and DWI changesSource 4: P.L. 2025, c. 41 — Interlock time frames (N.J.S.A. 39:4-50) |
| New Mexico | Required after every DWI conviction, including a first. To reinstate, you must hold an ignition interlock license with a device installed for at least 6 months. | 1 year for a first conviction, 2 years for a second, 3 years for a third, and for life after a fourth or later. | Source 1: NM MVD — General DWI InformationSource 2: NM MVD — How to Get an Interlock and Interlock Driver’s LicenseSource 3: NM MVD — Reinstatement Requirements |
| New York | Required for every DWI and Aggravated DWI conviction under Leandra’s Law, including first offenses. The court must order it as part of probation or a conditional discharge. | At least 12 months, unless the court allows earlier removal. It must be installed in any vehicle you own or operate. | Source 1: NY DMV — Leandra’s Law and Ignition Interlock DevicesSource 2: NY DCJS — FAQ About DWI and Leandra’s Law |
| North Carolina | Required to get your license back after a DWI conviction with an alcohol concentration of 0.15 or more, and after certain repeat convictions. A judge may also require it as a condition of a limited driving privilege. | The interlock stays for 1 year from restoration if the original revocation was 1 year, 3 years if it was 4 years, and 7 years if it was permanent. The restored license also carries a restriction against driving with an alcohol concentration of 0.02 or more. | Source 1: N.C. Gen. Stat. §20-17.8 — License restoration and ignition interlockSource 2: N.C. Gen. Stat. §20-179.3 — Limited driving privilege |
| North Dakota† | North Dakota relies on the 24/7 sobriety program rather than mandatory interlock. NDDOT may require an interlock as a condition of a temporary restricted license, and the Attorney General may allow interlock instead of twice-daily breath tests in 24/7. | If you are in 24/7, NDDOT issues a temporary restricted license after 14 days of the suspension. You must apply and file proof of financial responsibility and 24/7 participation. | Source 1: N.D.C.C. ch. 39-06 — Operators’ licensesSource 2: ND Legislative Council — DUI laws under 2013 legislation (memo) |
| Ohio† | Required to drive with a high test (0.17 or more) when the court grants driving privileges, and on repeat offenses. A first offender can petition for unlimited driving privileges with an interlock; if granted, the court suspends the jail term. | Length is set by the court order. Restricted yellow “party plates” are an alternative the court can order. | Source 1: Ohio Revised Code §4510.022 — Unlimited privileges with interlockSource 2: Ohio Revised Code §4510.13 — OVI license suspensions and limited privilegesSource 3: Ohio LSC — H.B. 388 final analysis (ignition interlock)Source 4: Ohio LSC — Bill analysis (March 15, 2022) |
| Oklahoma† | IDAP itself requires an approved ignition interlock. After a conviction, Oklahoma also requires interlock on vehicles you own or that are registered to you, including for aggravated DUI. | IDAP runs at least 180 days for a first revocation, 1 year for a second and 2 years for a third, and must end with a violation-free period (at least 90 days under SB 921). After conviction, the Highway Safety Office says interlock is 18 months for first-time offenders. | Source 1: 47 O.S. §6-212.5 — Impaired Driver Accountability Program (OSCN)Source 2: Enrolled SB 921 (2025) — IDAP amendmentsSource 3: Oklahoma Highway Safety Office — Alcohol Impaired |
| Oregon | Required after a DUII conviction, and during DUII diversion if your BAC was 0.08 or more, you refused a test, or drugs were found. Also required to get a hardship permit during a DUII suspension. | After the conviction suspension ends: 1 year for a first conviction and 2 years for a second or later conviction. Five years applies if the DUII came with a homicide or first-degree assault conviction from the same episode, or if privileges revoked for a third DUII are later restored. During diversion, you can ask the court to remove it after 6 months of compliance. | Source 1: Oregon DMV — DUII Convictions, Suspensions, Hardship Permits, and Reinstatements (Form 6826)Source 2: Oregon DMV — Hardship PermitsSource 3: Oregon Judicial Department — DUII Diversion Local Information HandoutSource 4: Oregon Revised Statutes, Chapter 813 |
| Pennsylvania† | Required for a second or later DUI. First offenders suspended at the High or Highest Rate, and drivers suspended for a refusal, can drive sooner with an Ignition Interlock Limited License. | One year after the suspension ends for repeat offenders. Driving without the device or tampering with it extends the requirement by 12 months. | Source 1: PennDOT DMV — Ignition Interlock FAQsSource 2: PennDOT — Ignition Interlock Limited License Eligibility Fact SheetSource 3: PennDOT DMV — DUI Legislation (penalty tables) |
| Rhode Island | On a first DUI the judge may bar you from driving without an interlock and/or blood and urine testing, and must do so at 0.15 or more. The judge must order it on a second or later DUI and on a second or later refusal; on a first refusal it is optional. A hardship license is only granted by the sentencing court and only with interlock or blood and urine testing. | First DUI: a minimum 30-day suspension, then interlock or testing for 3 months to 1 year. A second DUI: a 45-day minimum suspension, then 6 months to 2 years of interlock or testing. A third DUI: a 60-day minimum suspension, then 1 to 4 years. Report a court-granted hardship license to the DMV Adjudication Office to get the restriction added. | Source 1: R.I. Gen. Laws §31-27-2.8 — Ignition interlock systemSource 2: R.I. Gen. Laws §31-27-2 — Driving under influence of liquor or drugsSource 3: RI DMV — Hardship License/Ignition Interlock |
| South Carolina | Since May 19, 2024, the “All Offender” law requires every driver convicted of DUI to join the Ignition Interlock Device Program, regardless of BAC. Interlock can also end a refusal or 0.15+ administrative suspension early. | Length depends on the offense and BAC. For an administrative suspension, the device stays on for the time remaining on the suspension. | Source 1: SCDPS — All Offender interlock law announcement (May 2024)Source 2: SCDPS — Impaired Driving LawsSource 3: S.C. House Legislative Update, April 8, 2014 (Emma’s Law) |
| South Dakota† | Not automatic on a first DUI. Anyone on probation, parole, or a suspended sentence for DUI must have at least one monitoring tool: the 24/7 Sobriety Program, an ignition interlock, an alcohol monitoring bracelet, or similar. | Length is set by the court as part of supervision. Many people are also put on 24/7 twice-daily breath testing (around 7 a.m. and 7 p.m. at the sheriff’s office) as a bond condition after arrest. | Source 1: 2026 Session Law (HB 1126) — Revise a provision related to DUISource 2: SD Attorney General — 24/7 Sobriety ProgramSource 3: SD Attorney General — 24/7 bond conditions with interlock (form) |
| Tennessee | Required to drive on a restricted license during any DUI revocation, and on a restricted license after an implied consent violation. You need a court Order for Restricted Driver License (ORDL), proof of SR-22 insurance, and proof of installation. | The interlock is required for the full revocation period, with a 365-day minimum. Revocation periods: 1 year (1st), 2 years (2nd), 6 years (3rd), 8 years (4th or later). | Source 1: Tennessee Dept. of Safety — Ignition Interlock and DUI revocation periodsSource 2: Tennessee Dept. of Safety — How long do I have to have an interlock?Source 3: Tennessee Dept. of Safety — I got a DUI, now what? |
| Texas† | Required as a condition of community supervision for a second or later DWI, and for a first DWI with a BAC of 0.15 or higher. Courts can also order it as a bond condition. | Length is set by the court order (bond or community supervision). An interlock-restricted license may be needed to drive during a suspension. | Source: Texas DPS — Alcohol-Related Offenses |
| Utah† | The court must order an interlock as a condition of probation after a DUI conviction unless it finds on the record that one is not necessary. For drivers under 21 it is mandatory. At 0.16 or more the court must order an interlock, an ankle monitor, or home confinement, or explain why none fits. A second DUI within 10 years requires an interlock on every vehicle you own or drive. | 18 months after a conviction for drivers 21 and older; 3 years for drivers under 21 at arrest. Longer for felony and repeat convictions. | Source 1: Utah Driver License Division — Ignition Interlock DeviceSource 2: Utah Code §41-6a-518 — Ignition interlock devicesSource 3: Utah Code §41-6a-505 — DUI sentencing (effective July 1, 2026)Source 4: Utah Highway Safety Office — Utah’s DUI Laws |
| Vermont | An ignition interlock RDL lets you drive during a suspension in an interlock-equipped vehicle (not a commercial vehicle). It is optional for a first offense and required before reinstatement for a second or later offense. Refusal cases must wait 30 days (first), 90 days (second) or 1 year (third or later) before applying, and cases involving death or serious bodily injury must wait 1 year. | A first offender who chooses an RDL must operate under it for the length of the suspension (90 days for a first alcohol failure) before reinstatement. A second offender needs 18 months on an RDL. A third or later offender must drive on an interlock RDL for at least 3 years before the Total Abstinence program can reinstate them. Violations and failed retests can extend these periods. | Source 1: Vermont Statutes — 23 V.S.A. § 1213 (ignition interlock RDL)Source 2: Vermont Statutes — 23 V.S.A. § 1209a (conditions of reinstatement)Source 3: Vermont Statutes — 23 V.S.A. § 1205Source 4: Vermont DMV — License Suspensions and Related ProgramsSource 5: Vermont DMV — Ignition Interlock DeviceSource 6: Vermont DMV — Ignition Interlock Program FAQSource 7: Vermont DMV — What is an Ignition Interlock RDL?Source 8: Vermont DMV — Total Abstinence Reinstatement |
| Virginia† | Required as a condition of any restricted license after a DUI conviction, and as a condition of getting your full license back after a second offense or a first offense at 0.15 or more. | At least 6 months with no violations before the interlock can come off. The court and VASAP monitor compliance. | Source 1: Va. Code Title 18.2, Chapter 7, Article 2 — Driving while intoxicatedSource 2: Va. Code § 18.2-270.1 — Ignition interlock systemsSource 3: Virginia DMV — Restricted Driving PrivilegesSource 4: Virginia Courts — Application for Restricted Driver’s License (DC-263) |
| Washington† | Required after a DUI or Physical Control conviction or deferred prosecution. An ignition interlock driver license lets you drive during a DOL suspension if you install a device. | 1 year for a first violation, 5 years for a second and 10 years for a third or later. Carrying a passenger under 16 adds 6 months. | Source 1: Washington DOL — Ignition interlock device (IID)Source 2: Washington State Patrol — Ignition InterlockSource 3: RCW 46.20.720 — Ignition interlock durationSource 4: RCW 46.61.5055 — Penalty schedule |
| West Virginia | The Motor Vehicle Alcohol Test and Lock Program lets many revoked drivers drive with an interlock after a shorter hard revocation. It is optional for most first offenses and the route back to driving for many repeat offenders. | First offense at 0.08 to 0.149: 15 days revoked, then 125 days of interlock. At 0.15 or more: 45 days, then 270 days. First refusal: 45 days, then 1 year. | Source 1: W. Va. Code §17C-5A-3aSource 2: WV DMV — Alcohol & Drug Test and Lock Program Revocation Interlock Information (DMV-308-SE) |
| Wisconsin† | Required for a first OWI with an alcohol concentration of 0.15 or more, for every repeat OWI, and after an improper refusal. | The court sets the length of the interlock order. You also need an interlock-restricted occupational license to drive during a revocation if one is ordered. | Source 1: Legislative Fiscal Bureau — Intoxicated Driver Laws (Jan. 2023)Source 2: WisDOT — OWI and related penalties chart |
| Wyoming | Required after a first DUI conviction at 0.15 or more, and after every second or later conviction. The court may order the 24/7 sobriety program as an alternative to, or in addition to, the interlock. | 6 months for a first conviction at 0.15 or more, 1 year for a second, 2 years for a third, and for life after a fourth or later (you may ask the court to remove it after 5 years). The interlock time starts once the interlock restricted license is issued. | Source 1: Wyoming Statutes Title 31 — Motor VehiclesSource 2: WYDOT — Ignition InterlockSource 3: WYDOT — Driving Privilege Withdrawal |
From each state’s guide, which links the official sources. Educational information, not legal advice. † Still being verified against official sources; check the linked source before relying on it.
How an interlock works
An ignition interlock is a breath tester wired to the vehicle’s ignition. You blow into it before the engine starts and, in most programs, again at random intervals while driving. A reading above the program’s limit keeps the car from starting and is logged for the monitoring agency.
The interlock is ordered by the court, by the licensing agency, or both, and the two orders can run on different clocks. Read the interlock overview for the general picture and your state guide for the rule that applies to you. The hearing deadline is usually the first date that matters.
Common questions
- Do I need an ignition interlock after a first DUI?
- It depends on the state. Some states require an interlock after any DUI conviction, some only for a high BAC, a refusal, a repeat offense or a child passenger, and some leave it to the judge. The table lists each state’s trigger in the words of its guide, with the official source.
- How long does an ignition interlock stay installed?
- The period is set by statute, the court order or the licensing agency, and often grows with each offense or with a high BAC. The “Duration and how it is set” column gives each state’s rule.
- Who pays for the interlock?
- In most states the driver pays the vendor for installation, monitoring and removal. Costs are set by vendors and vary, so this page does not quote them; the state guide links the official program page.
- Can I drive without an interlock if one is required?
- No. Driving a vehicle without a required interlock, or having someone else blow into it, is a separate offense in most states and can extend the interlock period or the suspension.
- Is the interlock the same as a hardship or restricted license?
- They are different but often paired. A restricted or hardship license lets you drive during a suspension, and many states make an interlock a condition of it. See the restricted license section of your state guide.
Read your state’s guide
Every number on this page links to the state guide that explains it, with the official source.
All 50 state guides →
Related guides
Educational information, not legal advice. Each row comes from that state’s DUI911 guide and the official statute, licensing agency or court page it cites. Laws change and every case is different; confirm the deadline on the paperwork you were given and talk to a licensed attorney in your state.