Auto insurance coverage which protects the insured's property up to his/her policy limit for property damage that results from an accident with a legally liable uninsured, identifiable motorist.  This coverage is only available if the insured does not purchase collision coverage (as UMPD would provide some duplicate coverage).  With UMPD coverage, most companies will not provide coverage for property damage from a legally liable uninsured, unidentifiable motorist (e.g., a hit-and-run driver) - though such damage may be paid if you carry collision coverage.  This coverage may not be available in all states and may be subject to a deductible.
A coverage in an Automobile Insurance policy under which the company will pay losses to the insured for UMPD for which another motorist is unable to pay because he is uninsured. This coverage applies to property damage losses only. By law, in California, insurance companies must offer this coverage. If you do not want this coverage you must specifically reject it.
Uninsured motorist property damage coverage is available in some states, where it's often mandatory. This kind of auto insurance coverage protects you if your vehicle is damaged in an accident caused by a driver who has no car insurance. Other protection afforded by this type of auto insurance coverage varies from state to state. The amount covered by uninsured motorist bodily injury is capped at the limit you choose when you buy your auto insurance policy. In some states, you'll need to pay a deductible each time you file an auto insurance claim.