What Most People Get Wrong About UM Coverage
The instinct: you are a careful driver with good liability limits, so you are covered. Uninsured motorist coverage sounds like an add-on for people who want extra protection they probably will not use.
What's actually true: your liability coverage protects other people from you. It does nothing at all when someone else causes the crash and cannot pay for it — and in Arizona that scenario is not rare. Roughly one in eight Arizona drivers has no insurance, and this is an at-fault state where the person who caused the damage owes it. When that person has no policy and no assets, the only coverage standing between you and your own medical bills is the UM coverage on your own policy.
What to do instead: read your declarations page and find out whether you actually have it, because a great many Arizona drivers declined it years ago on a phone call they no longer remember. Then set the limits to match your liability limits rather than leaving them at some minimal figure — the coverage is inexpensive relative to what it does.
Almost every conversation about car insurance focuses on what happens when you cause an accident. This one is about the opposite situation, which in Arizona is statistically more worth worrying about: someone else causes it, and they have nothing. Roughly one in eight drivers in this state carries no insurance at all, and Arizona law puts the cost of a crash on the driver who caused it — a rule that stops being useful the moment that driver has no policy and no assets. Uninsured motorist coverage is the answer to that problem, and it is the coverage Arizona drivers most often turn down without quite realizing they did.
- AZ uninsured
- ~1 in 8Drivers, IRC estimate
- UM covers
- No insuranceOr hit-and-run
- UIM covers
- Not enoughLimits too low
- The law
- Must be offeredARS 20-259.01
What is uninsured motorist coverage?
Short answerIt stands in for the liability coverage the other driver should have had.
The cleanest way to hold it: uninsured motorist coverage substitutes for the at-fault driver's missing policy. It pays for bodily injury to you and your passengers in situations where there is no other insurance to turn to.
It responds in three distinct scenarios:
The at-fault driver has no insurance at all. The straightforward case, and in Arizona a common one.
The at-fault driver cannot be identified. A hit and run leaves you with nobody to pursue, and this coverage generally treats an unidentified driver as uninsured.
The at-fault driver's insurer is insolvent. Under Arizona's definition, an insured vehicle still counts as uninsured if the liability insurer cannot pay because it has become insolvent.
One important boundary: this is bodily injury coverage. Damage to your own vehicle is handled elsewhere — typically by collision coverage, or by uninsured motorist property damage coverage where that is offered separately. Ask which route your own policy uses, because it determines whether a deductible applies.
What's the difference between UM and UIM?
Short answerUM is for no coverage at all. UIM is for coverage that runs out.
These are two separate coverages that are frequently sold together and just as frequently confused.
| Uninsured motorist (UM) | Underinsured motorist (UIM) | |
|---|---|---|
| The other driver has | No liability insurance | Insurance, but not enough |
| Also covers | Hit-and-run, insolvent insurer | Limits exhausted by damages |
| What it pays | Bodily injury to you and passengers | The shortfall above their limits |
| Required in Arizona? | Must be offered, not required | Must be offered, not required |
UIM deserves more attention than it usually gets, because of a quirk in Arizona's own rules. The state minimum is 25/50/15 — $25,000 of bodily injury per person. A driver carrying exactly that is fully legal and badly underinsured for any serious injury. A hospital stay, surgery and rehabilitation can pass $25,000 without difficulty.
So the realistic Arizona picture is not just "some drivers have nothing." It is that a large additional group carries the legal minimum, which is itself thin. UIM is the coverage that answers the second group.
Why does this matter more in Arizona?
Short answerA high uninsured rate combined with at-fault liability is a bad pairing for the innocent driver.
Those two facts have to be read together, because either alone would be manageable.
In a no-fault state, your own policy pays your medical costs regardless of who caused the crash, so an uninsured at-fault driver is less catastrophic for you personally. Arizona does not work that way. Here, liability follows fault — which is a sensible rule right up until the liable party has no policy, no assets and no realistic ability to pay a judgment.
You can win that argument completely and collect nothing. A judgment against someone with nothing is a piece of paper. Uninsured motorist coverage is the mechanism that converts your own premium into an actual source of recovery, and it is the only one available in that scenario.
What does Arizona law require?
Short answerInsurers must offer it in writing. You are not required to buy it.
The governing statute is ARS 20-259.01, and its structure is worth understanding because it explains why this coverage gets declined so often.
The statute requires every insurer writing auto liability policies in Arizona to make uninsured motorist coverage available to the named insured and to offer it by written notice, and at the insured's request to include it in the policy — in limits not less than the bodily injury liability limits contained in the policy. Underinsured motorist coverage is addressed on the same footing. The Arizona Department of Insurance provides a form used for selecting limits or rejecting the coverage.
So: the offer is mandatory, the purchase is not. Which means most Arizona drivers were offered this coverage at some point, and anyone who does not have it declined it — frequently during a phone call years ago, while focused on the total premium rather than on what was being given up.
Worth noting for completeness: whether and how a rejection must be documented has been litigated in Arizona, and courts have addressed what happens when a carrier cannot produce evidence of a proper offer or rejection. That is a question for a lawyer on a specific claim, not something to rely on in advance. The reliable move is simply to check your declarations page and see what you actually have.
What limits should you carry?
Short answerMatch them to your liability limits — the statute is built around that idea.
The simplest defensible rule is to set UM and UIM equal to your bodily injury liability limits. The statute itself frames the offer in those terms, and the logic holds up: the amount of protection you think is appropriate for injuring someone else is a reasonable measure of the protection you would want if someone injures you.
Two things follow from that.
If your liability limits are low, both problems are low. A driver on 25/50/15 who matches UM to it has $25,000 of protection against an uninsured driver, which is thin for a serious injury. Raising liability limits and UM together is the coherent move.
Revisit them together. If you increase liability at renewal and leave UM where it was, the two drift apart and you have quietly capped your own recovery.
Cost is rarely the obstacle people expect. UM and UIM are generally inexpensive relative to liability coverage, because they are triggered less often. If premium is the real constraint, there are levers that lower the bill without lowering what the policy pays — this is not the place to economize.
How do you find out what you actually have?
Short answerYour declarations page, in about two minutes.
Most Arizona drivers genuinely do not know whether they carry this coverage, which is the practical problem underneath everything above.
Pull your declarations page — the summary page listing your coverages and limits, not the full policy booklet.
Look for two separate line items: uninsured motorist and underinsured motorist. They may be abbreviated UM and UIM. If a line shows no coverage, rejected, or simply is not there, you do not have it.
Compare those limits to your bodily injury liability limits. If they do not match, find out why — usually it is a decision made once and never revisited.
Ask how your own vehicle would be covered in an uninsured-driver crash, and whether a deductible applies.
One further check while you have the page open: confirm that every vehicle on the policy carries the same UM and UIM limits, because Arizona's statute permits an insurer to require matching limits across vehicles owned by the named insured. A mismatch is worth understanding before a claim rather than after one.
If any of that turns out differently than you assumed, you are in ordinary company. This is the most commonly misunderstood coverage on an Arizona auto policy, and the gap almost always traces back to a single conversation nobody wrote down.
The Bottom Line
Uninsured motorist coverage answers the situation Arizona makes most likely and least controllable: someone else causes the crash and has no way to pay for it. With roughly one in eight drivers here carrying no insurance, and an at-fault system that puts the bill on the person who caused the damage, a judgment against an uninsured driver is often worth exactly nothing. UM and UIM convert that dead end into an actual source of recovery.
Arizona law requires that this coverage be offered to you in writing under ARS 20-259.01, at limits not less than your bodily injury liability limits. It does not require you to accept it — which is why so many drivers declined it years ago and have not thought about it since. Two minutes with your declarations page will tell you which group you are in. Raquel Jimenez Insurance in Tucson will read it with you and price matching limits across our markets, at no charge. Call (520) 889-5766.
Related Questions Arizona Drivers Ask
What is uninsured motorist coverage in Arizona?
Uninsured motorist coverage pays for bodily injury to you and your passengers when the at-fault driver has no liability insurance, cannot be identified as in a hit and run, or is insured by a company that has become insolvent and cannot pay. It steps into the place of the coverage the other driver should have carried. It is bodily injury coverage, so damage to your vehicle is handled by collision coverage or by separate uninsured motorist property damage coverage where offered.
What is the difference between UM and UIM?
Uninsured motorist coverage applies when the at-fault driver has no insurance at all, cannot be identified, or whose insurer is insolvent. Underinsured motorist coverage applies when the at-fault driver does have liability insurance but the limits are not enough to cover the damages. Given that Arizona's minimum property damage limit is $15,000 and its minimum bodily injury limit is $25,000 per person, an at-fault driver carrying the legal minimum can very easily be underinsured for a serious injury.
Is uninsured motorist coverage required in Arizona?
No, it is not mandatory to purchase. But ARS 20-259.01 requires every insurer writing auto liability policies in Arizona to make uninsured and underinsured motorist coverage available and to offer it to the named insured by written notice, in limits not less than the bodily injury liability limits in the policy. So the offer is required even though the purchase is not, and the Arizona Department of Insurance provides a form used for selecting or rejecting the coverage.
How many Arizona drivers are uninsured?
Estimates place Arizona among the higher states in the country, with the Insurance Research Council's figure commonly cited at roughly one in eight drivers. That matters more here than it would in a no-fault state, because Arizona is an at-fault state where the driver who causes a crash owes the damage. When that driver has no policy, there is frequently nothing meaningful to collect against, and your own uninsured motorist coverage becomes the practical source of recovery.
Does uninsured motorist coverage apply to a hit and run?
Generally yes, because a driver who cannot be identified falls within the definition of an uninsured motor vehicle for these purposes. That is one of the most valuable functions of the coverage, since a hit and run leaves you with an at-fault party who cannot be pursued at all. Reporting requirements and the specific terms vary by policy, so report the incident promptly to law enforcement and to your insurer, and check your own policy language.
Last reviewed by Raquel Jimenez on July 26, 2026. The requirement that Arizona insurers make available and offer uninsured and underinsured motorist coverage by written notice, in limits not less than the policy's bodily injury liability limits, is ARS 20-259.01, which also treats a vehicle as uninsured where the liability insurer is insolvent. Arizona's 25/50/15 minimum limits are set by ARS 28-4009. The uninsured driver share reflects Insurance Research Council estimates as commonly cited for Arizona. Policy terms, reporting requirements and property damage treatment vary by contract. This is general information, not legal advice, and not a substitute for advice on your specific policy.