California requires uninsured motorist coverage, and it works differently than liability insurance

California law requires you to carry uninsured motorist (UM) coverage as part of your auto insurance policy. Unlike liability coverage, which pays for damage you cause to someone else, UM coverage pays for your own injuries and vehicle damage when the other driver has no insurance or not enough insurance. The state sets minimum amounts you must carry, and you cannot waive this coverage entirely — though you can reject it in writing if you understand what that means.

The law exists because roughly one in eight California drivers are uninsured, and another portion carry only the state minimum liability limits. If an uninsured or underinsured driver hits you, UM coverage steps in to cover your medical bills, lost wages, pain and suffering, and vehicle repair or replacement. Without it, you would have to sue the other driver personally — a process that often recovers nothing because uninsured drivers typically have no assets to collect from.

Key Takeaways

  • California requires UM coverage with minimum limits of $15,000 per person and $30,000 per accident for bodily injury, matching your liability limits or the state minimum, whichever is higher.
  • UM coverage pays for your own injuries and vehicle damage when hit by an uninsured or underinsured driver, not for damage you cause to others.
  • You can reject UM coverage only by signing a written form acknowledging you understand the risks — verbal refusal does not count.
  • Underinsured motorist (UIM) coverage is separate and covers the gap when the other driver's liability limits are too low to pay your full damages.
  • Your insurer must offer UM and UIM coverage at the same time, and the limits you choose affect your premium and what you can recover.

Minimum coverage amounts and how they are set

California's minimum UM limits are $15,000 per person injured and $30,000 per accident. These amounts must match your liability coverage limits or the state minimum, whichever is higher. If you carry $100,000 in liability coverage, your UM limits must be at least $100,000 per person and $300,000 per accident. The insurer cannot force you to carry UM limits lower than your liability limits.

These minimums cover bodily injury only — medical expenses, lost income, and pain and suffering. Property damage (damage to your vehicle) is handled separately under a different coverage type called uninsured motorist property damage (UMPD), which is optional in California. Many drivers add UMPD to cover repair or replacement of their car when hit by an uninsured driver, since collision coverage typically requires you to pay a deductible.

The difference between uninsured and underinsured motorist coverage

An uninsured motorist is someone driving with no liability insurance at all. An underinsured motorist is someone whose liability coverage is too low to pay your full damages. If you are hit by an uninsured driver and your damages are $50,000, your UM coverage pays the full amount (up to your limit). If you are hit by an underinsured driver whose liability limit is $25,000 and your damages are $50,000, their liability covers $25,000 and your underinsured motorist (UIM) coverage covers the remaining $25,000.

California requires insurers to offer UIM coverage whenever they offer UM coverage, and you must actively reject it in writing if you do not want it. Many drivers carry both UM and UIM with the same limits, since the combined coverage protects against both scenarios. Some policies allow you to set different limits for UM and UIM, though most insurers recommend keeping them equal.

How to reject uninsured motorist coverage in writing

You can refuse UM coverage, but only through a signed written form. Telling your agent verbally that you do not want it does not satisfy the law. Your insurer must provide you with a form that explains what UM coverage does, what the minimum limits are, and what happens if you reject it. You sign the form acknowledging you understand the risks, and the insurer keeps it on file.

If you reject UM coverage and are later hit by an uninsured driver, you have no coverage for your injuries. You can only sue the other driver directly, which usually means recovering nothing because uninsured drivers have no money or assets. Courts have upheld rejections made in writing, so the signature matters. If you later change your mind, you can request UM coverage again, though some insurers may require a new process or underwriting.

Stacking and how it affects your recovery

Stacking refers to combining UM limits across multiple vehicles or policies to increase the total amount available to pay your claim. California allows stacking in some situations but not others, and the rules are complex. If you own two cars with separate policies, each with $100,000 UM coverage, you may be able to stack them to access $200,000 total if you are injured in one of the cars. However, if you are injured as a passenger in someone else's car, stacking rules are different and depend on whether that car's policy allows it.

Your insurer will explain stacking options when you purchase or renew your policy. If you own multiple vehicles, ask whether your policies allow stacking and whether it makes sense for your situation. Stacking increases your premium but can significantly increase the amount available to cover serious injuries. This is one area where the specific language in your policy matters, so review it carefully or ask your agent to explain it.

What happens when you file a UM claim

If you are hit by an uninsured driver, you report the accident to your own insurer, not the other driver's (since they have no insurance). Provide your insurer with the police report, photos, medical records, and any information about the other driver. Your insurer will investigate to confirm the other driver was uninsured and determine what you are owed under your policy.

Your insurer may offer you a settlement, or you may need to go through arbitration or a lawsuit to resolve the claim. Unlike liability claims, where the other driver's insurer negotiates with yours, UM claims are between you and your own insurer. If you disagree with their settlement offer, you have the right to pursue the claim further. Many UM disputes end up in arbitration, where a neutral third party reviews the evidence and makes a binding decision. Having documentation of your injuries, treatment, and lost income strengthens your claim.

How UM coverage interacts with your other policies

UM coverage works alongside collision and comprehensive coverage, but they cover different things. Collision pays for damage to your vehicle from a crash, regardless of who caused it, but you pay a deductible. UM coverage pays for your bodily injury and lost wages, with no deductible. If you are hit by an uninsured driver, you would file a collision claim for vehicle damage (paying your deductible) and a UM claim for your injuries (paying nothing out of pocket).

If you have health insurance, it may pay your medical bills first, and your UM coverage becomes secondary — meaning it pays what health insurance does not cover. Some policies include a coordination of benefits clause that explains this order. Your homeowner's or renter's insurance does not cover car accidents, so UM coverage is your only protection for injuries from an uninsured driver. Review your policy to understand how these coverages work together in your situation.

Frequently Asked Questions

Can I reject uninsured motorist coverage and then change my mind later?

Yes, you can request UM coverage again at any time. However, some insurers may require a new process or underwriting, and your premium will increase retroactively to the date you request it. It is usually easier and cheaper to keep UM coverage from the start rather than drop it and add it back.

What if the uninsured driver is found and has assets — can I sue them directly instead of using my UM coverage?

You can pursue both. You can sue the uninsured driver in civil court for your full damages, and you can also file a UM claim with your insurer. If you win the lawsuit and collect money, your insurer may have a right to recover what they paid you from that judgment, depending on your policy language. Consult with an attorney before deciding which route to take, as the timing and strategy matter.

Does uninsured motorist coverage explore if I am hit while riding my bike or walking?

UM coverage on your auto policy typically does not cover injuries you suffer as a pedestrian or cyclist. You would need a separate uninsured motorist endorsement on your homeowner's or renter's policy, or a personal umbrella policy. Some states offer this coverage, but California's auto UM rules focus on vehicle-to-vehicle collisions. Check your homeowner's policy or ask your agent about pedestrian or cyclist coverage.

What is the difference between my UM limit and my deductible?

Your UM limit is the maximum amount your insurer will pay for your claim — for example, $100,000. Your deductible is the amount you pay out of pocket before coverage kicks in. UM coverage has no deductible, so if your limit is $100,000 and your damages are $50,000, you receive the full $50,000. Collision coverage, by contrast, has a deductible (often $500 or $1,000), so you pay that amount before the insurer covers the rest.

If I am hit by a driver with insurance but they do not have enough coverage, which coverage pays first?

The other driver's liability coverage pays first, up to their limit. Your UIM (underinsured motorist) coverage then covers the gap between what they paid and your full damages. For example, if their liability limit is $25,000 and your damages are $75,000, they pay $25,000 and your UIM coverage pays up to $50,000 (depending on your UIM limit). This is why carrying UIM coverage is important — many drivers carry only the state minimum liability, which is often not enough.