Ask the Car Insurance Expert
Would my grandma's car insurance cover me if I borrowed her car and got in an accident?
Generally standard car insurance policies extend coverage to relatives and friends who borrow the policyholder's car, so yes, your grandmother's policy would probably cover you, assuming you have a driver's license. Car insurance policies sometimes exclude coverage for unlicensed drivers, even if they have the owner's permission to use the car.
If you live with your grandmother, though, you should be listed as a driver on the policy. Household members who have regular access to the car should be insured under the owner's car insurance.
If you borrowed the car while visiting, then you wouldn't need to be listed on the policy to have coverage. However, in some states and under some policies, coverage may be reduced when you're operating the vehicle. Under so called "step-down provisions," car insurance liability protection is reduced to state minimum requirements for drivers who borrow the car. For more about step-down provisions, see Oh, you mean him? Why you should tell your insurer about your roommate.
The best way to be certain about coverage is to have your grandmother call her insurance agent or company to verify there will be full insurance protection when you use her car.