Who has to install one in Michigan
Law: MCL 257.625k, 257.625l, 257.319, 257.322a ยท read it
For the rule that applies to you, read your court order or the letter from the DMV.
A judge can order an interlock in other cases too. Your court order or DMV letter is what binds you.
Where each company can install in Michigan
You'll go back to the same company's locations for service for the whole order, so check that one is close to where you live and work before you book.
Locations as each company lists them on its own locator (Smart Start, Intoxalock, LifeSafer, RoadGuard), pulled Oct 2026. Some shops serve more than one company. Alcohol Detection Systems doesn't publish a locator we could read.
Interlock companies approved in Michigan
We couldn't read a current approved list for Michigan yet. The state agency linked in the sources has it.
Related guides
InterlockCompare is independent and doesn't make, sell or install interlocks. Not legal advice.