Why do I need underinsured auto insurance? I have great employer provided medical coverage. Won't that cover my injuries if I'm hit by an uninsured?

1) Under- or uninsured coverage would also help your passengers, who may not have great medical coverage.

2) Your medical coverage will only pay your medical bills--suppose you want to collect for other losses or injuries, including loss of wages owing to being hurt? Or medical costs like copays and deductibles not covered by your medical insurance? Or any treatment or therapy in excess of what your medical insurance would cover?

3) Suppose you lose or change your job and then no longer have such great coverage? Or your employer changes the paln, which is his/her/its right.

Your medical coverage won't pay for your lost wages, pain and suffering, or for permanent injury, in a serious accident.  I'm not a Pennsylvania lawyer, but my research suggests that the state minimum liability insurance policy limits are $15,000 per person and $30,000 per accident.  That isn't a whole lot, really, for any serious injury at all.  Underinsured coverage lets you have the benefits of a higher policy limit for any other driver that's liable to you, usually up to the coverage limit you pick for yourself.  It's usually not very expensive, and it's a great value.