Maryland Ignition Interlock Program

What is an Ignition Interlock? ​
An ignition interlock is a camera that connects a motor vehicle's ignition system to a tool that can detect and measure the alcohol level on a driver's breath. An ignition interlock will prevent a car from starting if the system detects alcohol. The data logger keeps a record of every transaction, along with the date, time, and alcohol level, any efforts to disable the device, make changes to the unit, as well as any request for random retest compliance. This information is reported to the appropriate monitor.​

For more frequently asked questions on the Ignition Interlock Program, click here.​

About Ignition Interlock Service Providers
Service providers will install, service and calibrate Ignition Interlock Systems. They will also provide training for interlock users. Service providers must install a device for eligible participants within 10 days of the request and provide a toll-free 24-hour emergency response number for all participants. Service providers have varying installation and monitoring charges. Service providers are required to offer the ignition interlock at 50% of their normal rental rate for customers who are on assistance.  If you are on assistance, please inquire directly with the interlock provider company for the reduced rental rate.

All Maryland Ignition Interlock Service providers  are required to offer accommodations to assist customers who are deaf or hard of hearing. Some vendors provide this accommodation in the form of an additional light bar attached to the dashboard which flashes when a test is required, some vendors have devices that offer visual and or vibration notification and some vendors offer a flashing LED that is integrated to work with the handset. ​

**All MVA-Authorized Ignition Interlock Service Providers offer different device features, training, installation, and customer support.  Please carefully review the provider websites to decide the service that works best for you.**

Alcohol Detection Systems -     ​1-888-786-7384

RoadGuard​ Interlock  -               1-800-332-6858

Guardian Interlock -                    1-800-499-0994

Intoxalock -                                     1-833-259-3046

LifeSafer  -                                     1-800-374-5760

Low Cost Interlock -                     1-844-276-0549

Sens-O-Lock                               410-995-9080

Smart Start Interlock  -               1-800-880-3394 


Learn more about what these service providers offer​ and read our best practices guide​ for additional information.​

Information for Participants​
Participants are responsible for all costs associated with the program participation. This includes the cost of the ignition interlock installation and a monthly servicing cost. Service providers have varying installation and monitoring charges. Service providers are required to offer the ignition interlock at 50% of their normal rental rate for customers who are on assistance.​​​