Uninsured Motorist vs. Collision Coverage: What's the Difference, and Do You Need Both?

Collision coverage pays to repair or replace your own car after a crash, regardless of who caused it, minus your deductible. Uninsured motorist coverage pays when you are hit by a driver who has no insurance, or not enough, and in the Texas Department of Insurance's words it also pays if you are in a hit-and-run accident. The two overlap on exactly one piece of a loss: damage to your car caused by an uninsured driver. Everywhere else they do different jobs. Collision never pays for your injuries, and uninsured motorist coverage never pays when you caused the crash yourself. Most drivers with a loan or a newer car end up wanting both, because each one fills a hole the other leaves open.

What collision coverage does

The Texas Department of Insurance describes collision coverage simply: it pays to repair or replace your car after an accident. California's Department of Insurance says it covers damage to your car caused by physical contact with another vehicle or an object, and its glossary lists examples such as a deer, tree, rock, guardrail, building, or person. Fault does not matter. Texas's glossary says collision pays for damage to your car without regard to who caused the accident, and that the company must pay for the repair or up to the actual cash value of your vehicle, minus your deductible. That last clause is the catch. You pay the deductible on every collision claim, whether you backed into a pole or an uninsured driver ran a red light into you.

What uninsured motorist coverage does

Uninsured motorist coverage, usually sold together with underinsured motorist coverage as UM/UIM, steps in when the at-fault driver cannot pay. Texas's glossary describes it as paying for your injuries and property damage caused by a hit-and-run driver or a motorist without liability insurance, and says it will also pay when your medical and car repair bills are higher than the other driver's liability coverage. The important words are at fault. Uninsured motorist coverage is a stand-in for the liability insurance the other driver should have carried. If you caused the crash, it does nothing.

The property damage half is where states diverge. In Texas, the Department of Insurance lists car repairs, replacement of the property in your car, medical bills for you and your passengers, a rental car, and even diminished value among the things UM/UIM can pay. In California, uninsured motorist property damage is a separate optional coverage with a $3,500 limit that only pays if the uninsured driver is identified. In some states uninsured motorist coverage is sold for bodily injury only. So before you assume your uninsured motorist coverage will fix your car, check whether your policy includes a property damage portion at all.

Where the two overlap, and where they don't

• An uninsured driver damages your car: collision pays minus your deductible, and uninsured motorist property damage pays where your policy includes it, often with a lower deductible. Texas's regulator puts that state's UM/UIM deductible at a flat $250 and notes the deductible on collision is likely much higher. That figure is Texas's rule.
• A hit-and-run: both can respond, with conditions. Texas says UM/UIM pays for a hit-and-run but will not pay if you did not report it to police. Washington's regulator requires a phantom-vehicle accident to be reported to police within 72 hours if you are making a claim.
• Your injuries: only uninsured motorist coverage. Collision never pays medical bills.
• A crash you caused, or a single-car accident with no other driver: only collision. Uninsured motorist coverage requires an at-fault driver who lacks insurance.

Do you need both?

If you carry collision, California's Department of Insurance says you may not need its uninsured motorist property damage coverage, because collision already pays for the car. That logic holds anywhere uninsured motorist property damage is sold: with collision in place, the property side of uninsured motorist coverage mostly saves you a deductible. The bodily injury side is a different question. Collision does nothing for your medical bills, so dropping uninsured motorist bodily injury because you have collision leaves you exposed to the worst-case crash, an uninsured driver who injures you. California requires insurers to offer uninsured motorist coverage, and if you decline it you must sign a waiver form. Many states have a similar offer-and-reject rule.

If you do not carry collision, the calculation flips. California's regulator advises drivers without collision to ask about uninsured motorist property damage. It is the only coverage on a liability-only policy that can pay for your car, and it only works when an identified uninsured driver is at fault, so it is a narrow backstop rather than a substitute for collision.

Which one to file under

When an uninsured driver damages your car and you carry both coverages, you usually get to choose. Texas's regulator notes that UM/UIM in that state carries the lower deductible and may also pay for a rental car and diminished value, which collision does not. In other states the deductibles may match, or the uninsured motorist property damage limit may be low enough that collision is the better route for a badly damaged car. Compare the deductible, the limit, and whether a rental is included before you pick. Either way, report a hit-and-run to police promptly, because both Texas and Washington tie coverage for unidentified drivers to a police report.

Collision is about your car and ignores fault. Uninsured motorist coverage is about the other driver's missing insurance, covers injuries first, and covers your car only where your state and policy include property damage. They overlap on one scenario, an uninsured driver damaging your car, and even there the deductibles and limits differ. For most drivers the practical answer is to carry both and let the overlap work in your favor.