If you’ve been injured in a car or truck accident in Missouri, there’s a real chance the at-fault driver’s insurance won’t cover all your losses. That’s where underinsured motorist (UIM) coverage can make a crucial difference. Below, we explain how UIM coverage works in Missouri, when it applies, and why consulting a car accident lawyer or truck accident lawyer near you can significantly strengthen your claim.
As a trusted Missouri injury law firm, we help clients every day navigate UIM claims—often after starting their search online for a car or truck accident attorney who understands Missouri law inside and out.
Why Missouri Minimum Insurance May Not Be Enough After a Serious Crash
Missouri drivers are only required to carry minimum liability insurance limits. In many injury cases, those limits are not enough to cover the full cost of a serious crash. A single emergency room visit, ambulance bill, surgery, hospital stay, follow-up appointment, or period of missed work can quickly exceed the amount available from the at-fault driver’s policy.
This is where underinsured motorist coverage can become important. If the other driver has insurance but their limits are too low to fully compensate you, your own UIM policy may provide an additional source of recovery. However, UIM benefits are not automatic. Your ability to recover depends on your policy limits, the at-fault driver’s limits, whether the other policy has been exhausted, and the exact language in your insurance contract.
Before accepting a settlement from the at-fault driver’s insurance company, it is important to confirm whether you have UIM coverage and whether your insurer requires notice or written consent before settlement.
What To Do After an Accident With an Underinsured Driver in Missouri
If you believe the other driver does not have enough insurance to cover your losses, take these steps before making any final decisions about settlement:
- Get medical care and continue following your treatment plan.
- Request the at-fault driver’s insurance information and confirm their available policy limits.
- Review your own auto insurance policy to see whether you purchased underinsured motorist coverage.
- Notify your insurance company that you may have a UIM claim.
- Do not sign a full release until you understand whether it could affect your right to pursue UIM benefits.
- Keep copies of medical records, medical bills, pay stubs, tax records, photographs, repair estimates, and all insurance correspondence.
- Speak with a Missouri car accident lawyer before accepting a settlement that may not cover the full value of your damages.
UIM claims often involve two separate insurance companies: the at-fault driver’s insurer and your own insurer. Even though your UIM claim is made through your own policy, your insurance company may still challenge the value of your injuries, the amount of coverage available, or whether the claim qualifies under the policy.
Common Mistakes That Can Hurt a Missouri UIM Claim
Underinsured motorist claims are highly policy-specific. A mistake made early in the claim can affect your ability to recover benefits later. Some of the most common issues include:
Settling Before Reviewing Your Own Policy
Many UIM policies require specific steps before you settle with the at-fault driver’s insurance company. If your policy requires written consent before settlement and you settle without it, your insurer may argue that you gave up your right to UIM benefits.
Accepting Less Than the At-Fault Driver’s Policy Limits
In many UIM cases, the at-fault driver’s available liability coverage must be fully exhausted before your own UIM coverage applies. If the other driver has $50,000 in available coverage, settling for less than that amount may create problems with your UIM claim.
Signing a Full Release Without Reserving the UIM Claim
A release should be reviewed carefully before it is signed. In some cases, the release should preserve your right to continue pursuing a UIM claim through your own insurance company.
Waiting Too Long to Notify Your Insurer
Your policy may require prompt notice of a potential UIM claim or notice of any lawsuit filed against the at-fault driver. Waiting too long can give the insurance company an argument against coverage.
Who May Be Covered by Underinsured Motorist Coverage?
Underinsured motorist coverage may protect more than just the person named on the insurance policy. Depending on the policy language, UIM coverage may apply to:
- The named policyholder
- Family members living in the household
- Passengers in the insured vehicle
- Pedestrians injured by an underinsured driver
- Bicyclists injured by an underinsured driver
- Motorcycle riders or passengers
- Other individuals covered under the policy’s definition of an insured person
Because UIM coverage is based on the wording of the insurance contract, the answer is not always obvious from the declarations page alone. A lawyer can review the full policy, endorsements, exclusions, and definitions to determine who may be covered and what benefits may be available.
What Evidence Helps Prove a UIM Claim?
To recover underinsured motorist benefits, you need to prove both the value of your damages and the limits of the available insurance coverage. Helpful evidence may include:
- Medical records
- Medical bills
- Future treatment recommendations
- Wage loss documentation
- Tax records or employment records
- Photographs of injuries and vehicle damage
- Police reports
- Witness statements
- Expert opinions
- Proof of the at-fault driver’s policy limits
- A full copy of your own auto insurance policy
The stronger the documentation, the harder it is for the insurance company to undervalue the claim. This is especially important when injuries involve long-term pain, permanent limitations, future medical care, or reduced earning capacity.
Other Sources of Compensation After an Underinsured Driver Accident
UIM coverage may be one source of compensation, but it is not always the only one. Depending on the facts of the crash, additional sources may include:
The At-Fault Driver’s Liability Coverage
Before a UIM claim applies, the at-fault driver’s available liability coverage usually needs to be identified and, in many cases, exhausted.
Medical Payments Coverage
If your own policy includes medical payments coverage, also known as MedPay, it may help pay certain medical expenses regardless of who caused the crash.
Other Liable Parties
Some crashes involve more than one responsible party. For example, a commercial vehicle accident may involve an employer, contractor, maintenance company, vehicle owner, or another negligent driver.
Personal Assets of the At-Fault Driver
In some cases, an injured person may consider pursuing the at-fault driver personally. However, if the driver carried only minimum insurance, they may not have enough assets to satisfy a judgment.
An attorney can help identify every available source of recovery before you accept a settlement that may close off important options.
What Is Underinsured Motorist (UIM) Coverage?
UIM coverage is designed to protect you when the driver who caused your accident doesn’t have enough liability insurance to fully cover your injuries and damages. While uninsured motorist coverage is mandatory in Missouri, UIM coverage is optional—but often essential.
According to the Missouri Practice Series, UIM coverage kicks in when your damages exceed the at-fault driver’s liability limits. Missouri law generally recognizes two types of UIM coverage:
- Gap coverage: Pays the difference between the at-fault driver’s insurance and the limits of your UIM policy.
- Excess coverage: Offers additional compensation beyond the at-fault driver’s limits, up to your own policy maximum.
At our firm, we regularly help clients understand how their policy is structured and what compensation they may be entitled to under Missouri law.
What Makes a Vehicle “Underinsured” in Missouri?
There’s no single definition. Missouri courts recognize two common interpretations, based on how your insurance policy is written:
- The at-fault driver is considered underinsured if their policy limits are lower than your UIM policy limits.
- A vehicle is underinsured if the at-fault driver’s limits are less than your total damages, even if both parties have the same coverage amounts.
For example, if the other driver has $50,000 in liability coverage but your medical expenses exceed that amount, your UIM coverage may step in—if your policy allows it.
Clients often discover that underinsured motorist language can be the deciding factor in what they’re able to recover financially. We help interpret these policy nuances every day.
Example: How UIM Coverage Works in Real Life
Underinsured motorist (UIM) coverage can be tricky—especially when the numbers suggest you're protected, but your policy says otherwise. Here are two common scenarios that illustrate how it works under Missouri law:
🚗 Scenario 1: You Have Less UIM Coverage Than the At-Fault Driver
- At-fault driver’s liability coverage: $100,000
- Your UIM coverage: $50,000
In this case, your UIM coverage likely does not apply. That’s because many Missouri policies only allow UIM benefits when your UIM limits exceed the at-fault driver’s liability coverage. Since your $50,000 in UIM is less than the other driver’s $100,000, your policy may not consider the vehicle “underinsured”—even if your actual damages exceed $100,000.
🚙 Scenario 2: You Have More UIM Coverage Than the At-Fault Driver
- At-fault driver’s liability coverage: $50,000
- Your UIM coverage: $100,000
- Your total damages: $125,000
Here, UIM coverage is likely to come into play. You would first collect the $50,000 from the at-fault driver’s policy. Then, you could claim up to $50,000 more from your own UIM policy to help cover the remaining damages—subject to your policy’s offset provisions.
This is a classic case of UIM doing what it’s meant to do: bridging the gap between what the other driver can pay and what you actually need.
Note: Whether or not your UIM benefits apply—and how much you can recover—depends entirely on your policy language. Some policies reduce your UIM benefits by what you’ve already been paid. Others don’t. Let a qualified Missouri injury lawyer review your coverage before you assume anything.
UIM Coverage Is Not Stackable in Missouri
While Missouri law often allows the stacking of uninsured motorist (UM) coverage, the same is generally not true for underinsured motorist (UIM) coverage.
Stacking means combining policy limits from multiple vehicles or policies to increase available coverage. For example, if a policyholder has three vehicles each with $50,000 in UM coverage, they might stack them to access $150,000 total. But most UIM policies include anti-stacking clauses that prohibit this.
Missouri courts have upheld such anti-stacking provisions in UIM policies as long as they are unambiguous and do not conflict with public policy. For example, in Rodriguez v. General Accident Ins. Co. of America, 808 S.W.2d 379 (Mo. 1991), the Missouri Supreme Court enforced an anti-stacking clause for UIM coverage, distinguishing it from mandatory UM coverage.
If the policy language is ambiguous, however, Missouri courts will construe the terms in favor of the insured and may permit stacking—even for UIM claims. This was the case in Manner v. Schiermeier, 393 S.W.3d 58 (Mo. 2013).
UM vs. UIM Coverage: What’s the Difference?
Uninsured Motorist (UM) coverage and Underinsured Motorist (UIM) coverage are not interchangeable—even though they sound similar.
- UM coverage protects you if you're hit by a driver who has no insurance at all. It’s required by Missouri law under § 379.203 RSMo.
- UIM coverage applies when the at-fault driver has insurance, but not enough to cover your damages. It is optional and based solely on the terms of your insurance contract.
In cases where the policy defines an underinsured motorist as a type of uninsured motorist, the rules for UM coverage may apply to UIM as well. For example, in Krombach v. Mayflower Ins. Co., 827 S.W.2d 208 (Mo. 1992), the court allowed stacking because the policy’s UM section included UIM under its definitions.
Understanding this distinction can make or break a claim. That’s why it's important to read your declarations page and policy definitions carefully—or have a qualified attorney do it for you.
An Underinsured Motorist Claim Is a Contract Claim: Why That Matters
Unlike a typical personal injury lawsuit, a UIM claim is a contract action, not a tort claim.
This classification has major consequences. For example:
- You cannot recover prejudgment interest under Missouri’s tort statutes.
- The statute of limitations may differ from that of a negligence claim.
- The measure of damages is based on your insurance contract, not directly on the tortfeasor’s conduct.
Missouri courts treat a UIM claim as a separate and distinct cause of action that arises only after you've exhausted the at-fault driver’s liability limits. As clarified in McKinney v. State Farm, 123 S.W.3d 242 (Mo. Ct. App. W.D. 2003), the claim is governed by contract principles—even though it requires proof of personal injury.
This means your rights (and limitations) are determined by the terms of your own policy—not just what happened in the accident.
How Do I Calculate My Damages in a UIM Claim?
To calculate your damages in a UIM claim, begin with what you’d calculate in a standard personal injury case:
- Medical bills (past and future)
- Lost wages and diminished earning capacity
- Pain and suffering
- Permanent disability or disfigurement
- Out-of-pocket expenses
Missouri courts use tort-based damages principles to assess UIM claims, even though the claim is contractual. As stated in Braughton v. Esurance Ins. Co., 466 S.W.3d 1 (Mo. Ct. App. W.D. 2015), the measure of damages mirrors that of a negligence claim.
However, your recovery is capped by your policy limits—and may be further reduced by "offsets" from other sources (like the amount paid by the at-fault driver’s insurer).
Knowing how to present and document your damages can dramatically affect the amount you're able to recover from your UIM insurer.
Final Tip: Why Policy Language Matters More Than You Think
Every UIM claim hinges on one thing: the exact language of your insurance policy.
Many people believe they’re covered just because they have UIM listed on their declarations page. But that’s not enough. Missouri courts routinely uphold exclusions, offsets, and anti-stacking clauses—if they’re clearly written.
Even minor differences in wording (e.g., whether coverage is excess or gap) can change the outcome of a claim. Courts will interpret ambiguous language in your favor—but only if you or your attorney identify those ambiguities and argue them effectively.
How to File a UIM Claim in Missouri
Missouri law places specific conditions on UIM claims. Notably, a claim typically doesn’t “accrue” until the at-fault driver’s policy is fully exhausted.
Here are important steps and rules to keep in mind:
- Notice is essential: You must notify your UIM carrier of any claim and of any lawsuit filed against the at-fault driver.
- Joinder is limited: Your UIM insurer generally can’t be joined in the same lawsuit unless the UIM claim has legally accrued.
- Lack of notice can hurt your claim: If your UIM carrier isn’t properly informed, they may not be bound by a judgment you win against the other driver.
As a Missouri personal injury firm, we routinely help clients follow these steps correctly so they don’t miss out on critical compensation.
UIM Coverage in Car vs. Truck Accident Cases
UIM issues arise in both car and truck accidents, but truck accident claims can be far more complex. Commercial insurance policies, multiple liable parties, and higher damages often make UIM claims more intricate.
Working with a seasoned truck accident lawyer near you—one who understands Missouri’s insurance landscape—can be the difference between a partial payout and full recovery. That’s why so many clients turn to us after a crash involving a commercial vehicle.
Don’t Delay: Protect Your Right to Compensation
Underinsured motorist coverage can be the financial safety net that protects you after a life-changing crash—but only if you understand how to use it.
If you’re searching for a car accident lawyer, truck wreck attorney, or just answers about your insurance policy, don’t wait. The sooner you talk to an experienced Missouri lawyer, the better your chance of securing the recovery you’re entitled to.
Contact the Missouri injury law firm of Uhrig & Brown today for a free consultation.
