Uninsured motorist coverage (often shortened to UM) covers the costs if your car is damaged by someone who doesn’t have insurance. It can also cover damage from a hit-and-run.
Uninsured motorist coverage is sometimes sold together with underinsured motorist coverage (UIM), though they do slightly different things. UIM insurance covers damage caused by drivers who are insured but don’t have enough car insurance to pay for the damage they caused. Some states require drivers to have both UM and UIM coverage.
What is uninsured motorist coverage (UM)?
Uninsured motorist coverage is a unique part of car insurance because it protects you and your vehicle from other drivers.
If someone who doesn’t have their own car insurance injures you or damages your car in an accident, your uninsured motorist coverage would cover the costs (up to your limits). Uninsured motorist coverage does not cover any damage that you cause.
Basically, uninsured motorist coverage acts like your replacement for an at-fault driver’s liability insurance if they don’t have any. Like your own liability insurance, uninsured motorists coverage is often broken into two types:
Uninsured motorist bodily injury (UMBI): Covers the cost of your medical bills if you’re injured by someone without their own car insurance.
Uninsured motorist property damage (UMPD): Covers the cost of repairing or replacing your property if it’s damaged by an uninsured driver.
How does uninsured motorist coverage work?
If you’re involved in a crash with an uninsured driver, you receive coverage up to the limits of your uninsured motorist coverage— and you don’t have to pay a deductible out of your final settlement.
The coverage offered by your uninsured motorist insurance may be shown with slashes, called split limits, like this: $25,000/$50,000/$50,000. In this example, your policy would cover:
$25,000 for each person who was injured in a crash
$50,000 total for everyone injured
$25,000 of damaged property
For example, imagine that an uninsured driver hit your car and caused injuries and damage, and you have underinsured motorist coverage with limits of $25,000/$50,000/$25,000.
Your injuries cost $20,000, while your passenger’s medical bills cost $24,000. Neither you nor your passenger’s injuries are greater than $25,000 — so you’re both fully covered by your uninsured motorist bodily injury coverage.
And any damage to your car in the crash would be paid for by your uninsured motorist property damage coverage, up to $25,000 worth.
Does uninsured motorist insurance cover hit-and-runs?
Uninsured motorist coverage can also cover damage from a hit-and-run, at least in some states. If your car is hit by a driver who speeds away from the scene, you wouldn’t need to chase them down to get their insurance information (if they were insured at all).
In states where it’s allowed, your uninsured motorist coverage would pay for the damage to your car after a hit-and-run.
However some states specify that uninsured motorist property damage (UMPD) doesn’t cover hit-and-run accidents, in which case you’d need to have collision coverage in order for the damage to be covered by insurance.
If the other driver is caught after your insurance company has already paid for the damage to your car, you don’t have to pay the money back. Instead, your company might pursue subrogation against the other driver — basically a process to recover their losses.
Uninsured motorist property damage vs. collision insurance
Although uninsured motorist property damage and collision coverage are both types of insurance that cover your own vehicle, they’re not the same types of coverage.
You can only use uninsured motorist coverage because of another driver’s actions. Collision coverage, on the other hand, can cover damage to your car that you or another driver causes.
Collision coverage (part of full-coverage insurance) can pay for damage caused by a driver without car insurance (like in the case of hit-and-runs in states where UMPD won’t cover the costs). But collision coverage is different because it can also pay for damage to your car from an accident you caused, like if you slam into a telephone pole.
What is underinsured motorist coverage?
Underinsured motorist coverage (shortened to UIM) is similar to UM, and they’re often written together, but they aren’t quite the same.
Unlike uninsured motorist protection, UIM covers damage caused by drivers who do have liability insurance — just not enough to fully cover an accident.
Your underinsured motorist coverage also comes in two forms:
Underinsured motorist bodily injury (UIMBI): Covers your medical bills, lost wages, and other costs related to the injuries from an accident with a driver who doesn’t have sufficient car insurance.
Underinsured motorist property damage (UIMPD): Covers the cost of repairing or replacing your car or other property after it’s damaged by a driver without enough car insurance.
In many states, uninsured and underinsured motorist coverages are bundled together into a single coverage (UM/UIM). You don’t have to worry about getting them separately.
When you’re required to get uninsured motorist coverage, you usually have to get underinsured coverage too. There are no states where you’d have to get UIM but not UM.
How does underinsured motorist coverage work?
Like uninsured motorist coverage, you would use your underinsured motorist coverage to cover damage or injuries caused by another driver.
But your underinsured motorist coverage would pay for damage when the at-fault driver has their own insurance, but not enough to cover the entire cost of the damage they caused.
Your underinsured motorist coverage is also displayed in split limits, like your liability insurance or UM coverage. However, since your underinsured motorist coverage works with the other insurance you have, things can get a little more complicated when it comes to claims.
Let’s say that your underinsured motorist bodily injury coverage is for up to $25,000 per person and $50,000 per accident.
You and two of your passengers are injured in an accident caused by an uninsured driver and have medical bills totaling $20,000 per person. The other driver has car insurance, but only for up to $40,000 per accident.
In this situation, the other driver’s liability insurance would cover $40,000 of your collective injuries (their policy’s maximum per accident). But how much your own policy would pay depends on whether you purchased reduced-by or add-on UIM.
Reduced-by coverage: Pays for the difference between your policy’s limits and the amount you received from the at-fault driver. In our example, you would have $10,000 of your own policy available to you after the at-fault driver pays out.
Add-on coverage: Pays up to the total of your insurance and the at-fault driver’s. In our example, your UIM would cover up to $90,000 for the entire accident.
Do I need uninsured and underinsured motorist coverage?
There are 23 states where you need uninsured motorist coverage (or must reject the coverage in writing) in order to drive legally. Usually, drivers who need uninsured motorist coverage must have UM limits that match their liability coverage limits.
Underinsured motorist coverage is required in 13 states. There are also a few states that only require underinsured motorist coverage if you get more than the state minimum of liability coverage. In these cases, your UIM coverage must match your liability limits.
Even if your state doesn’t require you to get uninsured or underinsured motorist coverage, or lets you waive the coverage, we still recommend drivers who can afford it get both types of coverage.
UM and UIM are usually available as a form of add-on coverage — and are the most affordable way to protect yourself from having to pay for expensive damage or injuries that aren’t your fault.
→ Read about your state’s insurance laws
States where you need uninsured and underinsured motorist coverage
State | UM required | UIM required |
---|---|---|
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
Optional | Optional | |
$25,000/$50,000/$5,000 | Optional | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
$25,000/$50,000 | Must match UM if driver purchases more than state minimums | |
$25,000/$50,000 unless rejected | Optional | |
Optional | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
$25,000/$50,000 unless rejected | Optional | |
Optional | Optional | |
$50,000/$100,000 | Must match UM coverage | |
$30,000/$60,000/$15,000 | $30,000/$60,000 | |
$20,000/$40,000 | Optional | |
Optional | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
Optional | Optional | |
$25,000/$50,000 | Optional | |
Must be rejected in writing | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
$25,000/$50,000 unless rejected | Optional | |
Must match liability limits if purchased | Must match UM if driver purchases more than state minimums | |
Must match liability limits | Must match liability limits | |
Optional | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
Must match highest liability limits | Must match UM if driver purchases more than state minimums | |
$25,000/$50,000 | Must match UM coverage | |
Optional | Optional | |
Optional | Optional | |
$25,000/$50,000 | $25,000/$50,000 | |
Optional | Optional | |
$25,000/$50,000 unless rejected | $25,000/$50,000 unless rejected | |
Must match liability limits | Optional | |
$25,000/$50,000 | Must match liability limits | |
Optional | Optional | |
Optional | Optional | |
Optional | Optional | |
$50,000/$100,000/$10,000 | $50,000/$100,000 | |
Must match liability limits if purchased | Must match liability limits if purchased | |
Optional | Optional | |
Must match liability limits | Optional | |
$25,000/$50,000 | Optional | |
Optional | Optional |
What is the cost of UM/UIM coverage?
Uninsured and underinsured motorist coverage are very cheap compared to other types of car insurance. The National Association of Insurance Commissioners reports that UM/UIM coverage costs just $65 per year on average — that’s just $5 per month. [1]
Given the affordability of uninsured motorist coverage compared to the amount of protection it can offer, we recommend that drivers add UM/UIM insurance to their policies even if their state doesn’t require it.
You won’t increase the overall cost of your auto insurance by much, and you could save yourself potentially hundreds or thousands of dollars in damages.
Coverage type | Average monthly cost | Average annual cost |
---|---|---|
Liability | $54 | $650 |
Collision | $32 | $381 |
Comprehensive | $14 | $172 |
UM coverage | $5 | $65 |
Source: NAIC’s 2018-19 Auto Insurance Database Report (2022)
Nationally, about 13% of drivers are uninsured, but the share of uninsured motorists can grow significantly depending on the state. In states with more uninsured motorists, costs are higher.
For example, in Florida and New Mexico, where there are higher numbers of uninsured drivers, UM/UIM costs $162 and $133, respectively.
Stacking uninsured and underinsured motorist coverage
Drivers in some states can “stack,” or combine coverage across vehicles or policies as a way to get more uninsured motorist coverage from a single company. Stacking your insurance is a way that a driver can use even more of their insurance coverage at once.
You might be able to stack your insurance if you insure multiple vehicles or have multiple policies with the same company. You can choose to combine the total UM coverage horizontally (across policies) or vertically (across vehicles).
If your company allows you to stack your uninsured motorist coverage, it might be worth the slight cost increase. By stacking, you enable yourself to use all of the coverage that you or your household is already paying for.