Uninsured vs Underinsured Motorist Coverage Costs Explained

Uninsured Motorist Coverage Costs: Compare Options

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Last updated on February 8, 2026

Jane Taylor
— Insurance content contributor

Jane Taylor contributes informational content for Loyainsurance.org, focusing on clear explanations of auto insurance concepts, coverage options, and common shopping considerations.

Articles may discuss typical pricing factors, discounts, payment options, and policy features in general terms to help readers compare options more confidently.

Content reviewed by the site’s editorial team for clarity, internal consistency, and accuracy of general insurance concepts.

Note: This bio describes a content role only and does not imply licensure, individualized advice, or affiliation with any insurer. Coverage availability, rules, and pricing vary by insurer and by state—always review your declarations page and policy forms for your specific terms.

Uninsured motorist (UM) and underinsured motorist (UIM) coverage exist for one reason: even when you do everything right, the other driver may have no insurance or not enough insurance to pay for serious injuries. In 2023, an estimated 15.4% of U.S. motorists were uninsured (about 1 in 7), and uninsured rates vary widely by state.[1][2]

This guide explains how UM and UIM coverage work, what drives their cost, and how to pick limits that match your real-world risk. If you want a quick side-by-side explanation first, start here:
uninsured vs underinsured motorist coverage.

Chart comparing monthly costs and coverage limits for uninsured and underinsured motorist insurance.

UM vs UIM: What They Cover (In Plain English)

UM and UIM typically focus on injuries (medical bills, lost income, and sometimes pain and suffering, depending on your state and policy). Some states also offer a related option for property damage caused by an uninsured driver. Your declarations page will show exactly which versions you have (UMBI, UIMBI, UMPD, etc.).

Uninsured motorist (UM) coverage commonly applies when:

The at-fault driver has no insurance.
You’re in a hit-and-run and the driver can’t be identified (coverage rules vary by state/policy).
You (or a covered family member) are struck as a pedestrian or cyclist by an uninsured driver (in many states).[3]

Underinsured motorist (UIM) coverage commonly applies when:

The at-fault driver has insurance, but their bodily injury limits are too low for your damages.
Your covered losses exceed the other driver’s liability limits, and your UIM can help “fill the gap” up to your policy limits (exact mechanics vary by state and policy language).[2][3]

Why UM/UIM Matters More Than People Expect

Many drivers assume the other driver’s liability coverage will handle a crash. The problem is that minimum required limits can be low, and not everyone buys (or keeps) insurance. The NAIC notes uninsured rates can range from single digits in some states to well over 20% in others (for example, NAIC cites a low of 5.7% in Maine and a high of 28.2% in Mississippi, based on IRC data).[2]

UM/UIM is also common because many states require UM and/or UIM or require insurers to offer it (often with a signed rejection if you decline).[1][3] That “offer/reject” paperwork matters—because people sometimes decline the coverage to save a small amount, then regret it after a serious accident.

What Drives the Cost of UM and UIM Coverage

UM/UIM is usually priced using many of the same variables that affect your overall auto premium. The biggest drivers are:

State rules and local risk: Legal requirements and local uninsured-driver rates can affect pricing.[1][2]
Your chosen limits: Higher UM/UIM limits generally cost more, but increase protection.
Driver profile: Age, driving history, claim history, and garaging location can influence premium.
Vehicle and household setup: Multi-car households may have stacking options (where allowed) that change pricing and available protection.

How Much Does UM/UIM Usually Cost?

Exact pricing is state- and driver-specific, but UM/UIM is often a relatively low-cost add-on compared with the overall policy. For example, Bankrate reports that adding UM coverage may cost roughly $5 to $25 per month depending on your profile and insurer.[4] Forbes Advisor has also reported an average annual cost figure for UM coverage (separate from the rest of the premium), reinforcing that it’s often modest relative to what a major injury claim can cost.[5]

Instead of relying on a generic estimate, use this simple approach: get quotes with the same liability limits, same deductibles, and the same UM/UIM limits, then compare the difference line-by-line. That’s the only way to see the real incremental cost in your ZIP code.

Example: “Apples-to-Apples” Comparison Template

Option	Example Limits	Best For	What to Double-Check
UM only	$50k / $100k	Areas with high uninsured rates; drivers who want baseline injury protection	Hit-and-run rules, exclusions, and whether UM property damage is separate
UIM only	$50k / $100k	Places where many drivers carry minimum limits; higher-income households	How your policy applies “offsets” or “gaps” versus the other driver’s limits
UM + UIM	$100k / $300k	Families, commuters, and anyone who wants stronger injury protection	Stacking availability (if you insure multiple cars) and any signed rejection forms

Important: This table shows a comparison method, not guaranteed pricing. Your insurer, state law, and policy language determine how benefits apply.

How to Choose the “Right” Limits (A Practical Method)

There isn’t one perfect number for everyone. But there is a reliable process that works for most households:

Step 1 — Match your liability (when possible): Many advisors recommend aligning UM/UIM limits with your bodily injury liability limits so you protect yourself at a similar level.[3]
Step 2 — Stress-test your finances: Ask, “If I had a serious injury and missed work, how long could my emergency fund cover my bills?”
Step 3 — Consider your passenger risk: If you frequently drive family members or carpool, higher limits often make more sense.
Step 4 — Quote two or three limit options: Example: $50k/$100k vs $100k/$300k vs $250k/$500k, then compare the monthly difference.

State Law and “Offer/Reject” Details (Why It Matters)

UM/UIM rules are heavily state-driven. Some states require it; others require insurers to offer it and allow you to reject it in writing.[1][3] In Florida, for example, the statute addresses how UM limits relate to bodily injury liability limits and allows selection of lower limits under the carrier’s rating plan.[6]

If you’re unsure whether you rejected UM/UIM in the past, ask your insurer for copies of any signed UM/UIM selection/rejection forms. It’s one of the fastest ways to catch a hidden coverage gap.

Will a UM/UIM Claim Raise My Rates?

It can, depending on your insurer, your state, your overall claim history, and the facts of the loss. Some insurers may treat frequent claims as a risk signal even if you weren’t at fault. The safest move is to ask your insurer how claims are handled in your state and to use UM/UIM for meaningful losses—exactly what it’s designed for—rather than minor expenses you could comfortably cover out of pocket.

Customer Experiences

How Drivers Think About UM/UIM in Real Life

These examples reflect common decision points drivers mention when reviewing UM/UIM (coverage comfort, paperwork, and understanding limits). Your experience will depend on your state and policy terms.

“I didn’t realize how many drivers carry minimum limits until my agent showed me the numbers for my state. We increased UIM, and the price change was smaller than I expected.”

— Policyholder, Las Vegas, NV

“The most helpful part was seeing a simple scenario: what happens if the other driver has low limits. That made our UM/UIM choice feel less abstract.”

— Family policyholder, Las Vegas, NV

FAQ

What is the difference between uninsured and underinsured motorist coverage?

UM helps if the at-fault driver has no insurance (or in certain hit-and-run situations, depending on your state and policy). UIM helps when the at-fault driver has insurance, but their limits aren’t high enough to cover your damages.[2][3]

How much does uninsured motorist coverage cost?

Pricing varies, but it’s often a relatively low-cost add-on. Bankrate reports that adding UM coverage may cost around $5 to $25 per month depending on your profile and insurer.[4] The best way to know your number is to quote two limit options with the same deductibles and liability limits.

Do I need both UM and UIM?

Many drivers choose both because the real-world risk isn’t only “no insurance”—it’s also “not enough insurance.” If you’re deciding, start by checking uninsured-driver rates and your state’s minimum liability limits, then price out two UM/UIM limit options to see the monthly difference.[1][2]

Can my rates increase if I make a UM/UIM claim?

It depends on your insurer, state rules, and your overall claim history. Ask your carrier how claims affect renewals in your state, especially if you’ve had multiple claims recently.

Are there discounts for UM/UIM?

Discounts usually apply to the overall policy (safe driver, multi-car, bundling, etc.) rather than UM/UIM alone, but they can still reduce your total premium.

Conclusion

UM and UIM coverage are about protecting your household from a very common financial blind spot: the other driver not having enough insurance. With uninsured motorists estimated at 15.4% nationally in 2023—and much higher in some states—UM/UIM can be a high-value layer of protection for many drivers.[1][2]

The best next step is simple: confirm your current limits, quote one higher limit option, and compare the monthly difference. If the cost increase is small, you may be able to meaningfully reduce out-of-pocket risk after a serious injury claim.

This article is for general educational purposes and does not replace personalized advice from a licensed insurance professional. Policy options, pricing, and requirements vary by state and insurer.

See your options

Want to confirm your current UM/UIM limits and see what higher protection looks like in real dollars? Review your declarations page, then compare quotes with the same deductibles and liability limits.

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