Arizona · Personal injury · Trial-ready representation
When the at-fault driver has no insurance — or not enough — your own UM/UIM coverage is often the only meaningful source of recovery. Here's how it actually works in Arizona.
Most people pay for UM/UIM coverage every month and have no idea what it does. After a crash with an uninsured driver — or, more often, with a driver carrying only Arizona’s bare-minimum policy — UM/UIM coverage is the difference between a real recovery and being told “they don’t have the money.”
The short version
Uninsured motorist coverage steps in when the at-fault driver:
Carried no liability insurance at the time of the crash
Arizona requires liability coverage, but a meaningful percentage of Arizona drivers are illegally uninsured.
Was driving a stolen vehicle
The owner's coverage may not extend to a thief.
Cannot be identified — a hit-and-run
In most cases, with corroborating physical evidence of contact.
Has insurance that denies coverage for the loss
Some carriers exclude business use, racing, and certain other circumstances.
When UM applies, your own carrier essentially steps into the shoes of the at-fault driver. You’re suing your own insurance company in form, but the case is built and tried like any other liability case.
Underinsured motorist coverage applies when the at-fault driver has liability insurance — but not enough. Arizona’s minimum liability limit is $25,000 per person and $50,000 per crash. A serious injury can generate medical bills several times that amount, plus lost wages and non-economic damages. UIM fills the gap up to your own UIM policy limits.
The math, simplified: if the at-fault driver has a $25,000 policy and your damages are $200,000, you collect the $25,000 from their carrier first. If your UIM coverage is $250,000, you can then pursue an additional $225,000 from your own carrier — bringing you closer to a fair recovery.
Arizona allows “stacking” of UM/UIM coverage in a wide range of circumstances. Stacking means combining the UM/UIM limits from multiple vehicles or multiple policies to increase the available coverage for a single claim.
Inter-policy stacking
Combining UM/UIM coverage across separate auto policies in the same household. If you have one policy on your car and your spouse has another on theirs, both may apply.
Intra-policy stacking
Combining UM/UIM coverage across multiple vehicles on the same policy. A single policy covering three cars at $100k UIM each may yield $300k of coverage in a single claim.
Resident-relative stacking
In many cases, a resident relative who lives in your household can access UM/UIM coverage from your policy if they're injured — even if the relative wasn't in your car at the time.
Whether stacking applies in a specific case depends on the policy language, the household relationships, and which vehicle was involved. Insurers do not volunteer that stacking is available; identifying it is part of what we do at the start of every case.
In a typical underinsured-driver case, the order of payment is:
1. At-fault driver's liability insurance
Pursue and resolve the bodily-injury liability claim against the at-fault driver's carrier first.
2. Get permission to settle from your UIM carrier
Most UIM policies require written consent before you accept the at-fault driver's policy limits. Skipping this step can void UIM coverage. We handle this routinely.
3. Pursue UIM
Once the underlying liability claim is resolved (or limits are tendered), the UIM claim against your own carrier moves forward.
4. Stack additional policies if available
Identify and pursue stacking across vehicles, household policies, and umbrella policies as the facts allow.
A personal umbrella policy can add an extra $1 million or more of coverage on top of the underlying auto policy. Umbrellas often include their own UM/UIM provisions — but only if you specifically purchased that endorsement. Pull your umbrella declarations and look. If you have UM/UIM under the umbrella, the available coverage may be much larger than you assume.
The conventional advice — and ours — is to carry UM/UIM limits at least as high as your bodily-injury liability limits. The cost difference is small. The protection difference, in the wrong crash, is enormous. We have seen too many clients with $500,000 in liability coverage protecting the rest of the world and only $25,000 in UM/UIM protecting themselves.
If you take nothing else from this page: pull your auto declarations, look at the UM/UIM line, and decide whether the number you see is the number you want behind you the next time something goes wrong.
Free consultation
Every case is different. A short call with a Big Dog Law attorney can answer the question that actually matters for your situation.
