Ignition interlock requirements by state
Counting the 50 states and the District of Columbia together, at least 17 make every first DUI offender face interlock requirements. Each state's entry lists the trigger, the required length, the camera rule, any cost help and its source.
When an interlock is required by the state
- Any first DUI
- Certain first DUIs: a high reading, refusal or a restricted license
- Only by court order
| State | First DUI offense | How long | Camera | Help with the cost | Installers | Law and agency |
|---|---|---|---|---|---|---|
| Alabama | Only a high reading or a refused test | 90 days if BAC under 0.151 year if BAC over 0.15Repeat: 2nd: 2 years; 3rd: 3 years; 4th+: 4 years; refusal adds 1 year | – | Alabama Interlock Indigent Fund (1.5% of service center payments) |  from $50 a month4 companies | Ala. Code § 32-5A-191Alabama Law Enforcement Agency |
| Alaska | Every first offenseIIHS state table | Set in your court order or license letter | – | – | from $50 a month8 companies | Alaska Stat. § 28.35.030Alaska DMV |
| Arizona | Every first offense | 12 months (some may remove at 6)18 if BAC 0.20+Repeat: 2nd in 84 months: 12; 24 if 0.20+; aggravated/3rd: 24 months | Required | – | from $50 a month7 companies | Ariz. Rev. Stat. § 28-3319Arizona MVD |
| Arkansas | Every first offense | Equal to the driver's license suspension periodRepeat: Equals suspension: 2nd within 5 yrs: 24 months; 3rd: 30 months | Required | – | from $50 a month8 companies | Ark. Code Ann. § 5-65-118Arkansas Office of Driver Services |
| California | Only if the court orders one | Up to 6 months if court-ordered1 year if injuryRepeat: 2nd: 1 year; 3rd: 2 years; 4th+: 3 years; longer if injury | – | Income-based sliding scale: low-income drivers pay 10 to 90% of costs | from $50 a month8 companies | Cal. Veh. Code § 23575.3California DMV |
| Colorado | Only for a restricted license | 9 months if BAC below 0.152 years if BAC 0.15+Repeat: 2nd+: 2 years; habitual offender: 1+ year or rest of restraint | – | State income-based financial assistance account, up to $400 | from $50 a month4 companies | Colo. Rev. Stat. § 42-2-132.5Colorado DMV |
| Connecticut | Every first offense | 6 months (age 21+, elevated BAC)1 year for test refusalRepeat: 2nd conviction: 3 years; 3rd: lifetime, removal request after 15 years | – | Vendor discounted or no fees with a low-income letter from Social Services | from $50 a month7 companies | Conn. Gen. Stat. § 14-111(i)(2)Connecticut DMV |
| Delaware | Only for a restricted license | 5 months on IID license (first offense election) | – | – |  from $54.99 a month2 companies | 21 Del. C. § 4177GDelaware Division of Motor Vehicles |
| District of Columbia | Every first offense | 6 months1 year if refusal with no prior offense/refusalRepeat: 2nd: 1 year; 3rd+: 2 years; refusal with 2+ priors: 3 years | – | Department pays all costs if indigent (at or below 150% federal poverty guidelines) |  from $59.99 a month2 companies | D.C. Code § 50-2201.05aDistrict of Columbia DMV |
| Florida | Only a high reading or a refused test | At least 6 months if court-ordered, or BAC 0.15+ or minor in carRepeat: Minimums: 2nd 1 year (2 if BAC 0.15+/minor); 3rd 2 years; 4th+ 5 years | – | Court may apply DUI fine to install cost; vendor discounts | from $50 a month8 companies | Fla. Stat. § 316.1937Florida DHSMV |
| Georgia | Only if the court orders oneIIHS state table | Set in your court order or license letter | – | Financial hardship exemption from installing interlock (O.C.G.A. § 42-8-111(a)(1)) | from $50 a month4 companies | O.C.G.A. § 42-8-111Georgia DDS |
| Hawaii | Every first offense | One yearRepeat: 2nd: 18 months; 3rd: two years | Required | Interlock company provides reduced-cost devices for indigent offenders | from $54.99 a month2 companies | Haw. Rev. Stat. § 291E-41Administrative Driver's License Revocation Office |
| Idaho | Every first offense | Ends 1 year after suspension period ends, unless exception grantedRepeat: 2nd within 10 years: required after 1-year suspension; 1 year from installation | Required | Court interlock device fund, based on financial hardship | from $50 a month6 companies | Idaho Code § 18-8008Idaho Transportation Department |
| Illinois | Only for a restricted license | During suspension: 6 months (failed test), 12 months (refusal)Repeat: 2 or 3 convictions: 5 continuous years for full reinstatement | Required | Indigent BAIID Fund pays vendor fees; Secretary of State fees still owed | from $50 a month8 companies | 625 ILCS 5/6-206.1Illinois Secretary of State |
| Indiana | Only if the court orders oneIIHS state table | Set in your court order or license letter | – | – | from $50 a month6 companies | Ind. Code § 9-30-5-16Indiana official page |
| Iowa | Only for a restricted license | 180 days before full reinstatement, if no prior revocationRepeat: 2+ offenses: 365 days after reinstatement; temporary restricted license: 365 days or its length | – | – | from $50 a month7 companies | Iowa Code § 321J.4Iowa DOT |
| Kansas | Every first offense | 180 days after completing suspension1 year if certain priorsRepeat: One year if records show certain prior convictions or license actions | – | Reduced costs: pay 50% if income at or below 150% poverty level | from $50 a month6 companies | K.S.A. 8-1015Kansas Department of Revenue |
| Kentucky | Only for a restricted license | 4 months, if 90 consecutive violation-free days met within first 4 monthsRepeat: 2nd: 12 months; 4th+: 30 months (120 violation-free days) | Required | Reduced fees per federal poverty guidelines via Affordability Application TC 94-188 | from $50 a month6 companies | Ky. Rev. Stat. Ann. § 189A.340Kentucky Transportation Cabinet |
| Louisiana | Only a high reading or a refused test | Entire 2-year suspension if BAC 0.15+at least 6 months if refusalRepeat: 2nd, BAC 0.15+: 4-year suspension; 2nd+ on probation: probation period | – | Economic hardship (SNAP, Medicaid, SSDI or a public defender): pay at most 50% of fees | from $50 a month6 companies | La. R.S. 32:378.2Louisiana Department of Public Safety and Corrections |
| Maine | Only for a restricted license | Remaining term of 150-day suspension, after serving 30 daysRepeat: 2nd: 2 years; 3rd: 3 years; 4th+: 4 years | – | At least 50% cost cut if income at or below 150% poverty guidelines | from $50 a month4 companies | Me. Rev. Stat. tit. 29-A, § 2508Maine Secretary of State |
| Maryland | Every first offense | 6 months the first time required to participateRepeat: 2nd participation: 1 year; 3rd or later: 3 years | Required | $47 fee waiver; 50% rental discount for assistance recipients | from $50 a month7 companies | Md. Code Ann., Transp. § 16-404.1Maryland MVA |
| Massachusetts | Only for a restricted license | Through the length of the hardship license (if BAC .15+)Repeat: 2+ OUI convictions: minimum two years | – | RMV Indigency Program waives certain vendor costs | from $50 a month5 companies | Mass. Gen. Laws ch. 90, § 24½Massachusetts RMV |
| Michigan | Only a high reading or a refused testIIHS state table | Set in your court order or license letter | Required | Free device if income below 150% poverty line; $2/day maintenance | from $50 a month6 companies | MCL 257.625kMichigan Secretary of State |
| Minnesota | Only for a restricted license | 30 daysunder 21: 180 days; BAC 0.16+ or refusal: 1 yearRepeat: 2 in 20 years: 2 years; license canceled as a danger to public safety: 3 to 6 years minimum | Required | Discounted rate for indigent participants; reduced fees, one vehicle | from $50 a month8 companies | Minn. Stat. § 171.306Minnesota Driver and Vehicle Services |
| Mississippi | Only for a restricted license | Period prescribed by the courtRepeat: 3rd: 3 years; 4th+: 10 years (interlock-restricted license only) | – | – | from $50 a month4 companies | Miss. Code Ann. § 63-11-31Mississippi Department of Public Safety |
| Missouri | Only a high reading or a refused test | At least 6 months from license reinstatement, when requiredRepeat: 2nd+: at least 6 months from license reinstatement | – | – | from $50 a month7 companies | Mo. Rev. Stat. § 302.440Missouri Department of Revenue |
| Montana | Only if the court orders oneIIHS state table | Set in your court order or license letter | – | – | from $50 a month5 companies | Mont. Code Ann. § 61-8-1010Montana Motor Vehicle Division |
| Nebraska | Only if the court orders one | As court determines, not exceeding maximum possible revocation term | – | DMV Ignition Interlock Fund pays indigent drivers' costs, if funds available | from $50 a month8 companies | Neb. Rev. Stat. § 60-6,211.05Nebraska Department of Motor Vehicles |
| Nevada | Every first offense | At least 185 days12 to 36 months if BAC 0.18+Repeat: 2nd: at least 185 days if BAC under 0.18; 0.18+: 12 to 36 months | Required | – | from $50 a month8 companies | Nev. Rev. Stat. § 484C.460Nevada Committee on Testing for Intoxication |
| New Hampshire | Only if the court orders one | Aggravated DWI: 12 months to 2 yearsRepeat: Subsequent: 12 months to 2 years, after revocation/suspension | – | Hearing for credit up to 75% of installation/service cost | from $50 a month4 companies | N.H. Rev. Stat. Ann. § 265-A:36New Hampshire DMV |
| New Jersey | Every first offense | 3 months7 months to 1 year if BAC 0.10+; 12 to 15 months if 0.15+Repeat: 2nd or later: during forfeiture, then 2 to 4 years | – | Indigent persons pay 50% of installation and monthly leasing fees | from $50 a month8 companies | N.J.S.A. 39:4-50New Jersey MVC |
| New Mexico | Every first offense | 1 year for a first offenderRepeat: 2nd: 2 years; 3rd: 3 years; 4th+ (out-of-state convictions): life | – | Indigent fund: up to $50 install, $30/month, $50 removal | from $50 a month8 companies | NMSA 1978, § 66-8-102NMDOT Traffic Safety Division |
| New York | Every first offense | At least 12 months unless the court permits otherwiseRepeat: At least 12 months for any DWI | – | Court may waive costs or set payment plan if unable to pay | from $50 a month3 companies | N.Y. Veh. & Traf. Law § 1198New York Division of Criminal Justice Services |
| North Carolina | Only a high reading or a refused test | 1 year from restoration if original revocation was 1 yearRepeat: 3 years if 4-year revocation; 7 years if permanent revocation | – | – | from $50 a month5 companies | N.C. Gen. Stat. § 20-17.8North Carolina DMV |
| North Dakota | Only if the court orders oneIIHS state table | Set in your court order or license letter | – | – | from $54.99 a month2 companies | North Dakota official page |
| Ohio | Only if the court orders one | During suspension if court-ordered (from day 16)suspension may be halvedRepeat: Alcohol-related 2nd/3rd: remainder of suspension, from day 46 / day 181 | – | State indigent drivers interlock and alcohol monitoring fund | from $50 a month8 companies | Ohio Rev. Code § 4510.13Ohio Department of Public Safety |
| Oklahoma | Every first offense | At least 180 active interlock days plus Board participation criteriaRepeat: 2nd: at least 365 active days; 3rd+: at least 730 active days | – | – | from $50 a month8 companies | Okla. Stat. tit. 47, § 6-212.3Oklahoma Board of Tests |
| Oregon | Every first offense | Diversion: 1 year min (early removal possible)conviction: 1, 2, or 5 years min | Required | Costs may be waived or deferred if enrolled in SNAP | from $50 a month6 companies | Or. Rev. Stat. § 813.602Oregon State Police |
| Pennsylvania | Only a high reading or a refused test | 1 year or 18 months from restoration, by suspensionplus 60 clean daysRepeat: 1 year or 18 months from restoration, depending on suspension | – | Hardship exemption under 200% poverty: device in one vehicle only | from $50 a month8 companies | 75 Pa.C.S. § 3805PennDOT |
| Rhode Island | Only if the court orders one | 3 months to 1 year (interlock and/or blood/urine testing) | – | – | from $50 a month4 companies | R.I. Gen. Laws § 31-27-2.8Rhode Island courts and DMV |
| South Carolina | Every first offense | 6 monthsRepeat: 2nd: 2 years; 3rd: 3 years, 4 if within 5 years; 4th+: lifetime | Required | Interlock Device Fund; indigent may get 6 months' fees paid | from $50 a month5 companies | S.C. Code Ann. § 56-5-2941SC Department of Probation, Parole and Pardon Services |
| South Dakota | Only if the court orders oneIIHS state table | Set in your court order or license letter | Required | – | from $50 a month2 companies | S.D. Codified Laws § 32-23-23South Dakota Attorney General |
| Tennessee | Only for a restricted licenseIIHS state table | Set in your court order or license letter | Required | Interlock assistance under § 55-10-419; not for voluntary requesters | from $50 a month7 companies | Tenn. Code Ann. § 55-10-425Tennessee Department of Safety |
| Texas | Only a high reading or a refused test | At least 50% of supervision periodoccupational license: full suspensionRepeat: Not less than 50% of supervision period | – | Indigent: installation waived, monitoring fee halved (deferred adjudication) | from $50 a month8 companies | Tex. Transp. Code § 521.246Texas DPS |
| Utah | Every first offense | 18 months if 21+ at arrest3 years if under 21Repeat: Within 10 years of prior: 2 years; felony DUI: 3 years | – | Indigency affidavit; court may waive or allow installment payments | from $50 a month7 companies | Utah Code Ann. § 41-6a-518Utah Driver License Division |
| Vermont | Only for a restricted licenseIIHS state table | Set in your court order or license letter | Required | 50% device cost cut for benefit recipients; low-income fine halved | from $50 a month7 companies | 23 V.S.A. § 1213Vermont DMV |
| Virginia | Only for a restricted license | At least 12 consecutive clean monthscourt may allow 6 with extra restrictions | Required | Provider indigency fund; reduced fees if court declares indigency | from $50 a month4 companies | Va. Code Ann. § 18.2-270.1Virginia Alcohol Safety Action Program |
| Washington | Every first offense | At least 1 year (conviction or deferred prosecution)Repeat: 2nd: at least 5 years; 3rd+: at least 10 years | – | DOL indigent financial help: pays provider up to $80/month per service | from $50 a month6 companies | RCW 46.20.720Washington DOL and State Patrol |
| West Virginia | Only a high reading or a refused test | Min 125 days270 days if BAC 0.15+; 1 year if refused testRepeat: Min 2 years; +1 year per additional prior within 10 years | – | Install/removal fee waived for DMV-determined indigent persons | from $50 a month2 companies | W. Va. Code § 17C-5A-3aWest Virginia DMV |
| Wisconsin | Only a high reading or a refused test | Set by convicting courttypically a minimum of 12 months | Required | Reduced price if income below 150% of the federal poverty level, via convicting court | from $50 a month5 companies | Wis. Stat. § 343.301Wisconsin DMV |
| Wyoming | Only a high reading or a refused test | 6 months if BAC 0.15+Repeat: 2nd: 1 year; 3rd: 2 years | – | State pays half device costs for SNAP-eligible indigent drivers | from $50 a month5 companies | Wyo. Stat. Ann. § 31-7-401WYDOT |
What it costs: MADD's national range is $70 to $150 to install, $60 to $80 a month. Work out a total for your months.
Get the CSV of ignition interlock laws by state. Source: rows draw on each state's interlock statute and its DMV or program pages; the table was built from them.
When a state shows "Only if the court orders one", it means no law makes an interlock automatic after a first offense. In your case, a judge could still make you get an interlock.
With the "Only for a restricted license" label, you can avoid a device by staying off the road until the suspension is over. Only drivers who pick a restricted or early license to use during the suspension must have a device.
After one DUI, a court order and a DMV or licensing rule can both apply, each with its own length. When both apply to you, the device stays on until whichever lasts longer has run out.
Every row is drawn from that state's statute text plus the agency pages each row links to. Rows that no statute could confirm are marked "Not verified yet." If official pages are silent on a point, "Not stated in source" appears in the row. This isn't legal advice: your court order and DMV letter are the documents that decide your case.