An uninsured or underinsured motorist accident puts you in one of the most frustrating positions after a crash — the driver who hit you either has no insurance at all or not enough coverage to pay for your injuries. You did everything right, carried your own policy, and now you are stuck wondering who pays your medical bills, lost wages, and repair costs.
These cases are more common than most people expect. Nationally, roughly one in eight drivers carries no liability insurance, and many others carry only state-minimum limits that fall far short of serious injury costs. The good news is that options usually exist, but the claims process is different from a standard at-fault accident and the rules vary by state.
After the Crash is not a law firm and does not give legal advice. We connect people hurt in car accidents with independent, licensed attorneys in their area — at no cost to you for the initial review.
What Is the Difference Between an Uninsured and an Underinsured Motorist Claim?
The difference comes down to whether the at-fault driver has any coverage versus not enough coverage. Both situations leave you short, but the claims process and the policy language that applies can differ.
- Uninsured motorist (UM): The other driver has no liability insurance at all, or their policy was lapsed or invalid at the time of the crash. Hit-and-run accidents where the driver is never identified often fall into this category as well.
- Underinsured motorist (UIM): The other driver does carry insurance, but their policy limits are too low to cover the full extent of your damages. For example, if your medical bills and lost income total far more than the at-fault driver's policy can pay, the gap may be covered under your own UIM coverage.
Most states allow or require insurers to offer UM/UIM coverage as part of an auto policy. Some states make it mandatory. An attorney can confirm the rules that apply in your state and review how your own policy is written.
How Does Fault Work When the Other Driver Has No Insurance?
Fault is determined the same way it would be in any other crash — who violated a traffic law, acted negligently, or caused the collision. The difference is where the money comes from once fault is clear.
In a typical accident, you would file a claim against the at-fault driver's liability insurer. When that driver is uninsured, you generally file a claim under your own UM policy instead. You are essentially asking your own insurance company to step into the role the other driver's insurer would have played.
Comparative-fault rules still matter. If the state you were injured in reduces your recovery based on your own share of fault, your insurer may apply those same rules to your UM claim. An attorney familiar with your state's fault system can explain how this could affect your case.
What Injuries Are Common in Uninsured Motorist Accidents?
The injuries in these crashes are no different from any other car accident — what makes them harder is the financial gap left by the other driver's missing or thin coverage. Common injuries include at least five categories:
- Whiplash and other soft-tissue neck and back injuries
- Herniated or bulging discs
- Broken bones and fractures
- Concussions and traumatic brain injuries
- Knee, shoulder, and joint injuries requiring surgery or long-term therapy
When injuries are serious and the at-fault driver has no real coverage, the stakes of your own UM/UIM claim rise sharply. Gaps in medical treatment can weaken a claim regardless of how it is filed, so staying consistent with your doctors matters.
Which Insurance Policy Pays in a UM or UIM Claim?
In most cases, your own auto insurance policy is the one that pays through its uninsured or underinsured motorist provision. This can feel strange — you are making a claim against the company you pay premiums to — but that is exactly what UM/UIM coverage is designed for.
There are a few things worth understanding about how these claims typically work:
- Your insurer has a contractual obligation to pay covered losses up to your UM/UIM policy limits, but they also have a financial incentive to minimize what they pay.
- In underinsured cases, you may first need to collect the full limit of the at-fault driver's policy before your own UIM coverage kicks in. The sequencing rules vary by state.
- Some policies stack UM/UIM coverage across multiple vehicles on the same policy, which can increase available limits. Others do not. The language in your declarations page controls this.
An attorney can review your policy, identify every layer of coverage that may apply, and handle communication with your insurer.
What Are the Most Common Disputes in UM and UIM Claims?
The most frequent dispute is over how much your claim is actually worth. Because you are filing against your own insurer, the negotiation can feel adversarial in a way people do not expect.
Common disputes in these claims include at least four issues:
- Extent of injuries: Your insurer may argue your injuries are less serious than your medical records suggest or that some treatment was unrelated to the crash.
- Policy interpretation: Disagreements over whether coverage stacks, how UIM limits offset the at-fault driver's payment, or whether hit-and-run provisions apply.
- Valuation of damages: Insurers frequently undervalue pain, lost earning capacity, and future medical needs.
- Arbitration clauses: Many UM/UIM policies require disputes to go to binding arbitration rather than a lawsuit, which changes your legal options.
These disputes are a major reason people seek legal help in UM/UIM cases. An attorney who handles these claims regularly will know how your insurer typically operates and what evidence moves the number.
What Evidence Matters Most in an Uninsured Motorist Case?
The evidence that matters most is proof of the other driver's fault combined with thorough documentation of your own losses. Because your insurer was not at the scene and did not cause the crash, you need to build the case as if you were presenting it to a neutral party.
- The police report, which documents the other driver's information (or lack of it in a hit-and-run)
- Photos from the scene, vehicle damage, and visible injuries
- Complete medical records and billing from the date of the crash through ongoing treatment
- Proof of lost wages and any impact on your ability to work
- Your own insurance policy — the actual document, not just the declarations page summary
Preserving evidence early gives an attorney the strongest foundation to negotiate or present your claim in arbitration.
Why Does an Attorney Help in Uninsured or Underinsured Motorist Cases?
An attorney helps because you are negotiating against your own insurance company, and the process is structured to protect the insurer's bottom line, not yours. Many people assume their insurer will treat them fairly since they have been paying premiums for years, but UM/UIM claims are evaluated like any other liability claim.
A car accident attorney who handles UM/UIM cases can review your policy for all available coverage, document your damages properly, counter lowball offers with evidence, and represent you in arbitration if the policy requires it. Most attorneys who take car accident cases work on a contingency basis, meaning you pay nothing upfront and no fee unless there is a recovery. An attorney can confirm the fee arrangement before you commit.
Frequently Asked Questions
Do I have to have UM/UIM coverage to file a claim?
Yes — if your policy does not include uninsured or underinsured motorist coverage, this type of claim is generally not available. An attorney can review your policy to check.
Can I sue an uninsured driver directly?
You can, but collecting a judgment from someone who carries no insurance is often difficult. A UM claim against your own policy is usually the more practical path.
Is there a deadline to file a UM or UIM claim?
Yes. Statutes of limitations vary by state, commonly falling between two and three years, and your policy may impose its own shorter deadline. An attorney can confirm the timeline for your situation.
Will filing a UM claim raise my premiums?
It depends on your insurer and state regulations. In many states, insurers are restricted from raising rates on UM/UIM claims where you were not at fault, but practices vary.
If you were hit by an uninsured or underinsured driver, talking to a local car accident attorney is the fastest way to understand what coverage applies and what your claim may look like. After the Crash connects you with an independent, licensed attorney in your area for a free case review — no obligation, no cost to get started.