In the US, one can often add Uninsured and Underinsured Motorist coverage independently to one's car insurance. What exactly is the difference? It seems that, going by the name only, Underinsured should cover a strict subset of Uninsured since every person that is uninsured is also underinsured but not vice versa. The fact that one can add these coverages independenly suggests that there is more to that. Specifically, what is covered/not covered in the following scenarios:
- add only Uninsured
- add only Underinsured