As you are aware, Maryland state law requires 20/40/15 as the minimum insurance coverage on an automobile. These numbers stand for $20,000 per injured person up to a total of $40,000 for all injured persons in one accident for bodily injury liability insurance and property damage insurance of $15,000.

If someone cancels or let their insurance lapse in MD, they are required to turn in their license plates and registration card immediately to any Motor Vehicle Administration (MVA) office. The following penalties can be imposed by the MVA on an uninsured motorist in Maryland:

• Lose of license plates and vehicle registration privileges.
• Pay uninsured motorist penalty fees for each lapse of insurance - $150 for the first 30 days, $7 for each date thereafter.
• Pay a restoration fee of up to $25 for a vehicle's registration.
• Be prohibited from registering any future vehicles until all insurance violations are cleared.
• Have license plates confiscated by an authorized tag recovery agent, once registration suspension is in effect.
• Pay a fine of up to $1,000 and/or 1 year imprisonment if provided false evidence of insurance.

Also it is listed as a 5 point violation to be cited as driving without insurance, a violation of MD transportation code Title 17.

If you want to at-fault party to pay for the damages they caused and they will not willingly then you may need to take them to court and get a judgment against them. MD transportation code Title 17 sections 201 - 209 discusses what would then happen to the uninsured motorist if they do not pay on the judgment against them for the damages they caused.

In part this section of Maryland law says that if a person fails to satisfy a judgment within 30 days, the judgment creditor or his representative may send to the Administration a certified copy of the judgment and, on a form provided by the Administration, a certificate of facts relating to the judgment.

The administration shall then suspend the person's license to drive and the registration of all vehicles owned by the debtor within the state of Maryland. A license or registration suspended under this subtitle shall remain suspended and may not be renewed or reissued, and a new or original license or registration may not be issued to the judgment debtor until the judgment is either stayed, satisfied or has an installment payment of judgment plan that the court has to approve. 

You can get more information on the Maryland laws surrounding driving without insurance and being at fault in an auto accident by contacting the MD Insurance Department, MD MVA and/or a lawyer familiar with this area of Maryland law.