Medical payments coverage (also known as Med Pay) pays for reasonable and necessary medical expenses resulting from an auto accident. One nice thing about Medpay coverage, unlike UIM coverage, is that it is NOT fault-based. If you are driving your vehicle down the road, and you drive into a brick wall, and the accident is entirely your fault, your med-pay coverage still applies.
Your med-pay coverage also extends to every passenger in your vehicle at the time of the accident. Each occupant of the vehicle may recover up to the medpay limit (there generally is not a per incident limit).
Like UIM coverage, Med-pay coverage is also not vehicle-specific. Once again, it follows you and your family to protect them in any accident involving an automobile. Also, auto med-pay coverage applies to auto v. pedestrian accidents and accidents which occur when you are not in your own vehicle.
Note that your UIM insurer is generally entitled to an offset for the amount of any med-pay coverage paid by them.