Ignition Interlock Devices in Maryland: Requirements, Risks, and How to Avoid Costly Mistakes

Ignition interlock devices are often required after a DUI arrest or conviction in Maryland, but many drivers are unsure how they work, who needs one, and how compliance affects their driving privileges. Understanding these rules early can prevent additional penalties, extended license restrictions, and compliance issues with the Motor Vehicle Administration (MVA).

What Is an Ignition Interlock Device?

An ignition interlock device is a breath-testing system installed in a vehicle that prevents the engine from starting if alcohol is detected on the driver’s breath. Before starting the car, the driver must provide a breath sample, and random “rolling retests” may be required while driving to ensure continued compliance.

This device connects to the ignition system and measures blood alcohol concentration (BAC). If a driver’s BAC is above the calibrated limit set by Maryland law, the vehicle will not start.

Who Is Required to Install an Ignition Interlock in Maryland?

Under current Maryland Law, ignition interlock devices are mandatory for many drivers involved with DUI or DWI cases. Individuals convicted of an alcohol-related offense, including those receiving a Probation Before Judgment (PBJ) or a conviction for DUI or DWI, are typically required to participate in the ignition interlock program.

Maryland’s expanded ignition interlock requirements (often referred to under “Noah’s Law” changes) now apply to more offenders, including some first-time DUI cases depending on BAC and other circumstances.

Important: Participation with an interlock device is often required before full license reinstatement is considered.

For a deeper look at your options after a DUI charge, see our DUI Defense page.

How Long Is an Ignition Interlock Required?

The timeframe for using an ignition interlock device depends on the details of your case. Typical requirements include:

• First-time DUI offenses: commonly 6 months

• Second DUI offense: often 1 year

• Third or subsequent DUI offense: up to 3 years

If you have violations or compliance issues, the required period may be extended.

What Happens If You Violate the Ignition Interlock Program?

Ignition interlock violations can include:

• Failed breath tests with a BAC above allowed levels

• Ignoring or missing rolling retests

• Tampering with the device

• Using the vehicle without the interlock system installed

The service provider reports violations to the Maryland MVA. Consequences can include extended interlock periods, additional administrative penalties, or even reinstatement of a full license suspension.

Can a Lawyer Help With Ignition Interlock Issues?

Yes. A knowledgeable Maryland DUI attorney can help in several ways:

• Clarifying whether you’re required to install an interlock device

• Helping address alleged violations

• Communicating with the MVA or in court

• Exploring options to shorten restrictions or contest misreported data

If you’re facing ignition interlock requirements or have questions about compliance, legal guidance can help protect your rights and driving privileges.

Internal link: For more on legal support after a DUI, see our License Reinstatement guide.

What to Do If You’re Facing DUI Charges or Interlock Requirements

Don’t leave your situation to chance or general internet advice. The ignition interlock program is complex, and mistakes can extend your restrictions or lead to more serious consequences.

For official details on Maryland’s program and requirements, visit the Maryland MVA’s Ignition Interlock Program page.

If you’re unsure what steps to take next, contact our office for a thorough discussion of your case and options. Reach out to us using the contact our office to discuss your options.