While under insured or uninsured motorist coverage commonly goes by the name of UIM insurance, and it’s one of the best types of insurance you can buy, and you should buy as much as you can possibly afford. It’s not very expensive, and it covers you or a family member if you’re injured as a result of someone else’s negligence, and that person has no auto insurance or not enough. It also protects you if you’re a passenger in someone’s car, and you’re injured. It protects you if you’re walking, running, or even riding your bicycle. It’s wonderful insurance, won’t raise your premiums, and you really need to have it.