Ignition interlock laws by state

Whether a first DUI conviction means an interlock depends on your state. This table uses the IIHS state-by-state review (October 2026); each state guide goes further, with durations, fees, approved companies and removal rules quoted from the statute.

Full data table and CSV

Where a first DUI conviction means an interlockIIHS · October 2026

TexasRequired after a first conviction

First offense, to drive during the post-conviction suspension: yes, if license suspension imposed
First offense, as a penalty or to get the license back: no

Texas interlock guide

Required after a first conviction30 + DC
First offense: only at a high BAC6
Repeat convictions only7
Neither, by the IIHS definition7

IIHS counts a state when an interlock is required to drive during a post-conviction suspension, or to get the license back. Your own court order or DMV letter is what applies to you.

State	After a first conviction	Repeat conviction, as a penalty or to reinstate	Guide
Alabama	Required after a first conviction	yes	Full guide
Alaska	Required after a first conviction	yes	Basics
Arizona	Required after a first conviction	yes	Full guide
Arkansas	Required after a first conviction	yes	Basics
California	Repeat convictions only	yes	Full guide
Colorado	Required after a first conviction	yes	Full guide
Connecticut	Required after a first conviction	yes	Full guide
Delaware	Required after a first conviction	no	Basics
District of Columbia	Required after a first conviction	yes	Basics
Florida	First offense: only at a high BAC	yes	Full guide
Georgia	Repeat convictions only	yes	Basics
Hawaii	Required after a first conviction	yes	Basics
Idaho	Required after a first conviction	yes	Full guide
Illinois	Repeat convictions only	yes	Basics
Indiana	Neither, by the IIHS definition	no	Basics
Iowa	Required after a first conviction	yes	Basics
Kansas	Required after a first conviction	yes	Full guide
Kentucky	Required after a first conviction	no	Basics
Louisiana	Required after a first conviction	no	Basics
Maine	Repeat convictions only	no	Basics
Maryland	Required after a first conviction	yes	Full guide
Massachusetts	Repeat convictions only	yes	Basics
Michigan	First offense: only at a high BAC	yes	Basics
Minnesota	Repeat convictions only	yes	Full guide
Mississippi	Required after a first conviction	no	Basics
Missouri	First offense: only at a high BAC	yes	Full guide
Montana	Neither, by the IIHS definition	no	Basics
Nebraska	Required after a first conviction	yes	Basics
Nevada	Neither, by the IIHS definition	no	Basics
New Hampshire	Required after a first conviction	yes	Basics
New Jersey	Required after a first conviction	yes	Full guide
New Mexico	Required after a first conviction	yes	Full guide
New York	Required after a first conviction	yes	Basics
North Carolina	First offense: only at a high BAC	yes	Basics
North Dakota	Neither, by the IIHS definition	no	Basics
Ohio	Repeat convictions only	no	Full guide
Oklahoma	Required after a first conviction	yes	Basics
Oregon	Required after a first conviction	yes	Full guide
Pennsylvania	First offense: only at a high BAC	yes	Full guide
Rhode Island	Neither, by the IIHS definition	no	Basics
South Carolina	Required after a first conviction	yes	Basics
South Dakota	Neither, by the IIHS definition	no	Basics
Tennessee	Required after a first conviction	no	Full guide
Texas	Required after a first conviction	yes, when prior conviction occurred within the past 5 years	Full guide
Utah	Required after a first conviction	yes	Full guide
Vermont	Required after a first conviction	yes	Basics
Virginia	Required after a first conviction	yes	Full guide
Washington	Required after a first conviction	yes	Full guide
West Virginia	Required after a first conviction	yes	Basics
Wisconsin	Neither, by the IIHS definition	no	Full guide
Wyoming	First offense: only at a high BAC	yes	Basics

Source: IIHS, Alcohol interlock laws by state, October 2026. IIHS counts a state when an interlock is required to drive during a post-conviction suspension, or to get the license back.