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UM/UIM Coverage / Updated 18 April 2026

Uninsured Motorist Coverage: Why It's a Separate Decision from Full Coverage

UM/UIM is not part of liability and not part of full coverage. It is its own coverage -- and often the smartest $3-6/month you can spend, especially if you are dropping full coverage.

The Third Coverage Decision

Most coverage discussions focus on two choices: liability-only vs full coverage. But there is a third, separate decision that most competitor sites treat as a footnote: uninsured and underinsured motorist coverage.

UM (Uninsured Motorist) pays when the driver who hits you has no insurance at all. UIM (Underinsured Motorist) pays when the driver who hits you has insurance but not enough to cover your total damages. Both pay for your medical bills, lost wages, and pain and suffering -- not covered by liability or full coverage in an at-fault crash caused by someone else.

UM vs UIM vs UMPD

CoverageWhen It PaysWhat It CoversTypical Cost
UM (Uninsured Motorist)Other driver has NO insuranceYour medical bills, lost wages, P&S$3-6/mo (25/50)
UIM (Underinsured Motorist)Other driver's limits too lowYour excess damages above their payout$5-8/mo (100/300)
UMPD (UM Property Damage)Uninsured driver damages your carYour vehicle repairs$2-4/mo (25 states only)

Why UM/UIM Matters Most When You Drop Full Coverage

When you carry full coverage (collision + comprehensive), collision pays for your car's damage whether or not the other driver is insured. Drop full coverage and you lose that backstop. If an uninsured driver totals your $8,000 car, you have no recourse unless you carry either UM with a property damage component (UMPD) or can afford to absorb the loss directly.

In Mississippi -- where an estimated 30% of drivers are uninsured -- the expected probability that the driver who totals your car is uninsured is genuinely high. In states like Vermont (4% uninsured) the risk is much lower. UM/UIM is especially critical in the high-risk states below.

Uninsured Driver Rate by State (Selected States)

StateUNINSURED %UM/UIM Required
Mississippi30%Optional
Tennessee24%Optional
New Mexico22%Optional
Michigan22%Optional
Florida22%Optional
Washington21%Optional
Missouri21%Required
California21%Optional
Alabama19%Optional
New York17%Required
Rhode Island17%Required
Arkansas16%Optional
Colorado16%Optional
Alaska16%Optional
Kentucky14%Optional
Ohio14%Optional
Maryland14%Required
Delaware14%Required
Vermont7%Required
Maine4%Required

Source: Insurance Information Institute (III) 2024 data. Covers selected states with notable high or low rates; see the full state comparison table for all 50 states.

How Much UM/UIM Costs and What Limits to Buy

UM/UIM coverage is priced based on your chosen limits. The recommendation is to match your UM/UIM limits to your bodily injury liability limits. If you carry 100/300 BI liability, you should carry 100/300 UM/UIM.

UM/UIM LimitsTypical Monthly Cost
25/50$3-6/mo
50/100$5-9/mo
100/300$10-15/mo
250/500$18-25/mo

Related:

Cost by stateState minimums 2026When to drop full coverageLiability limit recommendations

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Frequently Asked Questions

What is uninsured motorist coverage?+
UM coverage pays your medical bills, lost wages, and sometimes car repair costs when you are hit by a driver with no insurance. UIM coverage pays when the other driver has insurance but not enough to cover your total damages. Both are typically $3-15/month depending on limits and are optional in most states.
Do I need UM coverage if I have full coverage?+
Yes, for different reasons. Collision covers your car's damage when hit by an uninsured driver, but collision does not cover your medical bills, lost wages, or pain and suffering. UM coverage fills that gap. Even with full coverage, UM adds an important layer for personal injury protection.
What state has the most uninsured drivers?+
Mississippi has the highest estimated rate at approximately 30%. Other high-risk states include Tennessee (24%), Michigan and Florida (22% each), Missouri and California (21% each). Data from the Insurance Information Institute, 2024.
How much does uninsured motorist coverage cost?+
UM/UIM coverage costs $3-6/month for 25/50 limits and $10-15/month for 100/300 limits. The recommendation is to match your UM/UIM limits to your bodily injury liability limits for consistent protection.
What is UMPD?+
Uninsured Motorist Property Damage (UMPD) is available in about 25 states and covers damage to your car when an uninsured driver hits it. It fills the gap for people who have dropped collision coverage -- if an uninsured driver damages your vehicle, UMPD pays for repairs without requiring full collision coverage.