What does underinsured motorist bodily injury coverage do?

Underinsured motorist bodily injury insurance (UNDUM) covers you, the insured members of your household (resident relatives) and your passengers in your insured car for bodily/personal injuries, damages, or death caused by an at-fault driver with insufficient insurance (is underinsured).  It also covers you and others listed on your insurance policy when riding in other cars.

Underinsured motorist bodily injury coverage varies according to the terms of your policy and state laws, but in general it pays the difference between what’s covered by the other driver’s insurance coverages, which can’t meet the amount of your damages, and the bodily injury limits listed on your policy.

Policy limits for underinsured motorist bodily injury coverage are per person and per accident and coverage is written as such.  For example $25,000/$50,000 means that the maximum payout per person is $25,000 and the maximum payout for all people injured in one accident is $50,000.  This coverage may also be simply written as 25/50.

If the UNDUM limits you purchase are lower than an accident’s costs, you’ll be responsible for paying the amounts over your limits, unless you’re covered by health insurance that will cover these medical expenses.

Underinsured motorist may be sold in combination with uninsured motorist coverage or sold separately depending upon the state and insurance carrier.

Is underinsured motorist bodily injury coverage mandatory?

Depending upon where you live, underinsured motorist bodily injury may be mandatory.  When underinsured motorist bodily injury coverage it is required, it may be bundled together with uninsured motorist coverage and referred to uninsured/underinsured motorist coverage. 

The insurance industry recommends underinsured motorist bodily injury liability coverage of $100,000 per person and $300,000 per accident (referred to as 100/300), if you can afford these higher limits.

What happens if I don’t have underinsured motorist bodily injury coverage?

If this coverage is optional in your state and you choose to go without, then you may be left to pay personally for medical expenses arising from accident caused by an underinsured motorist, unless the at-fault driver has the money to pay for your medical expenses that exceeded their bodily injury liability limits.

If you have adequate health insurance, then underinsured motorist bodily injury may be unnecessary. 

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Michelle Megna
Editorial Director

Michelle is a writer, editor and expert on car insurance and personal finance. Prior to joining CarInsurance.com, she reported and edited articles on technology, lifestyle, education and government for magazines, websites and major newspapers, including the New York Daily News.