Uninsured motorist (UM) coverage pays for your injuries and losses when the driver who hit you doesn’t have any liability insurance at all. Underinsured motorist (UIM) coverage does the same job when the other driver has insurance, but not enough of it to cover what you actually lost. Both live on your own auto policy, and both exist for one reason: because plenty of drivers on Colorado roads carry little or no insurance, and you shouldn’t be the one who pays for that.
Is it required in Colorado?
Colorado law (C.R.S. § 10-4-609(2)) requires insurers to offer you UM/UIM coverage in the same dollar amount as your bodily injury liability limits, typically at least $25,000 per person and $50,000 per accident under the state’s minimum liability limits (C.R.S. § 42-7-103(2)). You’re allowed to reject it, but only in writing. If you never signed a written rejection, there’s a good chance you already have this coverage and don’t realize it, which is worth checking before you assume you’re stuck.
What does it actually pay for?
UM/UIM coverage can pay for medical expenses, lost wages, and pain and suffering caused by an at-fault driver who can’t cover what they owe you. It also applies in hit-and-run situations, since an unidentified driver is treated the same as an uninsured one for these purposes.
What is “stacked” uninsured motorist coverage?
Stacking lets you combine UM/UIM limits across multiple vehicles on the same policy, or in some cases across multiple policies, to reach a higher total available coverage. Whether stacking is available and how it works depends on your specific policy, so this is a detail worth asking your insurance agent about directly rather than assuming either way.
One procedural trap worth knowing about
If you’re pursuing a UIM claim against your own insurer because the at-fault driver’s coverage wasn’t enough, many Colorado policies require you to get permission from your own insurance company before accepting a settlement from the at-fault driver’s insurer. Skip that step and you can jeopardize your own UIM claim. This is exactly the kind of detail that’s easy to miss if you’re handling a claim on your own.
Not sure what coverage you have?
If you were in an accident and you’re not sure whether UM or UIM coverage applies to your situation, that’s a quick conversation, not a research project. Call Mile High Legal at (720) 853-5779 for a free consultation, and bring your declarations page if you have it.
What to do next
If this is where you are right now, call Mile High Legal at (720) 853-5779 for a free consultation. We handle Colorado injury claims on contingency, meaning you pay nothing upfront and nothing at all unless we recover money for you.


