This is an optional coverage that increases the personal injury protection to you and the people in your car up to the amount of coverage purchased. It becomes effective when the party causing an accident has lower limits that you purchase and the accident costs more. The maximum dollars paid is then the difference between the two limits. For example, assume the under-insured motorist (UIM) limits selected were $100,000 per person and the person causing the accident had limits of $50,000 per person. Under this scenario, you could collect up to $50,000 from the at-fault driver and up to an additional $50,000 (the difference in limits) under your own UIM coverage. UIM coverage typically does not “add” the amount you purchased to the amount available from the person causing the accident. Insurers are required to notify policyholders who do not have UIM coverage of its availability. The limits of UIM coverage, if accepted after notification is $50,000 per person and $100,000 per accident.