UNINSURED & UNDERINSURED
MOTORIST CLAIMS

The two coverages

They get lumped together but they do different jobs.

Uninsured motorist (UM) applies when the at-fault driver has no liability insurance at all, or in a hit-and-run where the driver is never identified.

Underinsured motorist (UIM) applies when the at-fault driver has insurance, but not enough to cover what you've lost.

Both are optional in California. Insurers are required to offer them, and you can decline — but the rejection has to be in writing. If you never signed a written rejection, the coverage may be there even if you don't remember buying it. That's worth checking rather than assuming.

California's offset rule

This is the thing that surprises people, and it's specific to how California structures the coverage.

In many states, UIM sits on top of the at-fault driver's policy. If the at-fault driver pays $50,000 and you have $100,000 of UIM, you'd have $150,000 available.

California doesn't work that way. UIM here is reduced by what you recover from the at-fault driver. With $100,000 of UIM coverage and a $50,000 recovery from the at-fault driver, your UIM exposure is the remaining $50,000 — for $100,000 total, not $150,000.

The practical consequences:

Your UIM limit only helps if it's higher than the at-fault driver's limit. If you carry $30,000 of UIM and the at-fault driver carries $30,000 of liability, your UIM adds nothing.

And this is the argument for carrying more UIM than you think you need. It's usually inexpensive relative to liability coverage, and it's the coverage that protects you rather than the person you hit.

It follows you, not just your car

This is the most underused fact about UM/UIM.

The coverage typically follows the insured person. You may be covered when you're a pedestrian, when you're on a bicycle, when you're a passenger in someone else's car, and sometimes when you're a resident relative on a household member's policy.

If you were hit while walking or riding, do not assume your auto policy is irrelevant just because you weren't in your car. In hit-and-run cases involving pedestrians and cyclists, it's frequently the only available source of recovery.

Hit-and-run: the physical contact requirement

California generally requires actual physical contact between your vehicle or person and the hit-and-run vehicle to support a UM claim.

The practical effect is significant. If a driver runs you off the road without touching you — a "phantom vehicle" case — a UM claim is generally unavailable, however clearly the other driver caused the crash. Independent corroborating evidence of the contact is also typically required, meaning your own account alone may not be enough.

This is why the police report and any witness who saw the contact matter so much in these cases.

The steps, and the order

UM and UIM claims have procedural requirements that catch people.

Notify your carrier promptly. Policies contain notice requirements, and late notice can be a basis for denial.

Don't settle with the at-fault driver without your carrier's consent. This is the one that destroys claims. Your carrier has subrogation rights against the at-fault driver, and settling and releasing that driver without consent can forfeit your UIM claim entirely. Get written consent first.

Exhaust the at-fault policy first, in the usual sequence, before UIM responds.

Mind the separate deadline. California law requires that within a defined period — generally two years from the accident — you either file suit against the uninsured motorist, formally demand arbitration under the policy, or reach a settlement. Letting that period pass while negotiating can end the claim even though you were talking to your own insurer the whole time.

Your own insurer is now the opposing party

This is the part people find hardest. In a UM/UIM claim, the company you pay premiums to becomes the entity resisting your claim. They will evaluate your injuries, dispute your treatment, and argue about fault exactly as the other side's carrier would.

They do owe you duties they don't owe a third party — obligations of good faith in how the claim is handled. But the relationship is adversarial in substance, and it's a mistake to treat the claim as a friendly conversation.

Most UM/UIM disputes are resolved through arbitration under the policy rather than in court.