UM/UIM Stacking in Arizona After Roden v. Acuity: What Changed and How It Affects Your Settlement
If you’ve been told your prior auto policy maxed out at the bodily injury limit, the Arizona Supreme Court’s Roden decision may have just given you another six figures of coverage your adjuster forgot to mention.
For decades, Arizona auto insurance carriers told policyholders the same thing about uninsured and underinsured motorist coverage. “Sorry, you can’t stack policies. The bodily injury limit is the bodily injury limit. That’s it.”
That was never quite true even before Roden v. Acuity, but it became dramatically less true after the Arizona Supreme Court’s decision opened the door wider on inter-policy stacking. If your settlement was negotiated before you understood stacking, or your adjuster told you stacking wasn’t available, the case may be worth far more than what was paid.
What “stacking” actually means in plain English
Stacking is the process of combining UM/UIM coverage limits from multiple insurance policies (or from multiple vehicles on the same policy) to get a higher total available recovery. There are two types:
Intra-policy stacking applies when you have multiple vehicles on the same policy. If your three-vehicle policy carries $100,000/$300,000 UM/UIM on each vehicle, intra-policy stacking would let you reach into all three to get $300,000 total instead of just $100,000.
Inter-policy stacking applies when you (or a household member) are covered under multiple policies. Maybe you have your own policy plus your spouse has a policy plus your adult kid living at home has a policy. Each one might apply to your injury claim.
Arizona’s history on stacking is not a friendly one for plaintiffs. Insurance companies aggressively fought stacking with policy language, exclusions, and “anti-stacking” clauses. Many adjusters operate under the assumption that all stacking is barred. Roden reset that assumption.
What Roden v. Acuity changed
The case dealt with whether multiple UM/UIM coverages within a household could be combined when policy language tried to prohibit it. The Arizona Supreme Court read the policy exclusions strictly and limited an insurer’s ability to broadly bar stacking through boilerplate language.
The practical effect: more layered policies are now eligible to stack than carriers historically conceded. Where an adjuster five years ago might have refused to discuss inter-policy stacking, today the analysis must be done case-by-case based on actual policy language read against the Roden framework.
That doesn’t mean every Arizona case is now a stacking case. The policy language still matters. But it does mean that any case where an adjuster simply denied stacking without analyzing the policies should probably be revisited.
Practical example:
A.J., a Phoenix-area client, was told by an adjuster that his $50,000 settlement was the cap because his UM coverage was $50,000. Reviewing his household, his wife had a separate policy with $100,000 UM, and his adult son living at home had $25,000 UM. Under Roden, after careful policy review, the available stack was $175,000, not $50,000. The case re-opened, and the eventual recovery was over three times the original.
Who in your household might layer additional UM/UIM coverage
The Arizona definition of “household” for UM/UIM purposes is broader than people expect. A “resident relative” generally qualifies as a covered person under most household policies. Examples we routinely find:
- A spouse with a separate policy
- An adult child living in the home (even if they’re 25 and working)
- A parent who lives with the family
- A sibling who’s a temporary resident
- A college student claiming the family home as their primary residence
- A spouse’s vehicle on a different carrier from yours
Each of these may carry their own UM/UIM. Each policy needs to be reviewed. The cumulative coverage available is often shockingly higher than the single policy the adjuster wanted to write the check from.
What this means if your case already settled
Old cases can sometimes be reopened. The mechanisms vary:
Misrepresentation by the adjuster. If the adjuster affirmatively misrepresented stacking law to induce settlement, that may be grounds to set aside the release.
New policies discovered. If a household policy you didn’t know about turns out to provide additional coverage, you may have a new claim against that previously-undisclosed insurer.
Bad faith claims. If your own insurer denied stacking despite policy language that, under current law, allows it, you may have a first-party bad faith claim against your own carrier under Sloan v. State Farm doctrine.
Reopening prior settlements is hard but not impossible. The right move is a full policy review by counsel.
Frequently asked questions
How long after my settlement can I revisit stacking?
Arizona’s general statute of limitations for negligence is two years, but bad faith and misrepresentation claims can extend the window. The faster you act, the better. Don’t wait.
What if my adjuster sent me a letter “explaining” anti-stacking?
Bring it. Adjuster letters that misstate Arizona law in writing can become evidence of bad faith. Save every letter, every email, every voicemail.
Will stacking apply if I was a passenger, not a driver?
Often yes. Passenger UM/UIM analysis is layered through the vehicle’s policy plus any household policies of the passenger. The cumulative coverage can be substantial.
Does this apply to single-car crashes where I was hurt?
Yes, but with a twist. For a single-car crash, you’re typically reaching into your own UM/UIM (because there’s no “other driver” to claim against). Household stacking still applies.
The bottom line
If your case settled before 2024, or if your adjuster told you stacking wasn’t available without doing a full policy review, the case is worth a second look. The cost of having a lawyer review your prior policies and decline letters is zero. The downside is zero. The upside is sometimes six figures.
Free UM/UIM Stacking Review
We pull your prior policies, run them against current Arizona law, and tell you in 48 hours whether more coverage was available than you used.
Related: How AZ Adjusters Underpay Claims | UM/UIM Basics | AZ Personal Injury Overview
