Uninsured motorist coverage is part of a car insurance policy that helps pay for your medical bills if you're hit by a driver who doesn't have car insurance. Typically, when you're in an accident and the other driver is at fault, their auto liability coverage would help pay for your medical bills/injury, and/or repairs to your car. But if the at-fault driver doesn't have car insurance, you may have to pay out of your own pocket for those medical expenses. That's where Uninsured coverage may help.