Arizona Supreme Court Bars UIM Stacking Across Jointly Purchased Household Policies

Arizona Supreme Court Bars UIM "Stacking" Across Jointly Purchased Household Policies

The Arizona Supreme Court ruled on July 6, 2026 that a seriously injured crash victim could not combine, or "stack," underinsured motorist (UIM) benefits from three additional State Farm household auto policies his parents jointly purchased, in State Farm Mutual Automobile Insurance Co. v. Balzan, No. CV-24-0140-PR.

Information last verified on July 8, 2026. This is a developing story; we update it as the record changes.

Status: Decided July 6, 2026; opinion issued, affirming summary judgment for State Farm.

Jurisdiction scope: This ruling applies to Arizona auto insurance law and interprets Arizona's UM/UIM statute, A.R.S. § 20-259.01, as applied to State Farm's specific anti-stacking policy language. It does not decide how other insurers' anti-stacking clauses will be read, and it does not change Arizona's separate rules on liability coverage minimums. See the Arizona car accident laws overview for the broader claims picture.

What Happened

The case traces back to a 2019 Arizona crash in which the claimant, badly injured as he rode in a vehicle, suffered damages that exceeded what the at-fault driver's own liability insurance could cover. He turned to underinsured motorist coverage to close the gap.

He held his own State Farm UIM policy on a 2013 Hyundai Elantra, carrying $250,000 in per-person coverage. His parents separately held four more State Farm policies insuring other household vehicles, a 2001 Jeep Wrangler, a 2007 Mercedes S550, a 2016 Infiniti QX80, and a 2015 Kia Soul, each carrying the same $250,000 per-person UIM limit. He argued he was entitled to "stack," or combine, benefits across all five policies because each was a separately purchased contract with its own premium.

State Farm paid the claimant his own policy's UIM limit and the limit under one household policy, $500,000 combined, but refused to pay out the remaining three household policies. The insurer pointed to anti-stacking language in every policy limiting recovery to coverage "purchased by one insured," arguing that because the claimant's parents jointly bought the household policies, they counted as a single purchaser under that language, not four separate ones.

A trial court sided with State Farm on summary judgment. The Arizona Court of Appeals, Division One, took a different view in an unpublished 2024 decision, which would have allowed broader stacking. State Farm petitioned the Arizona Supreme Court for review, and the state's highest court agreed to resolve the conflict.

The Arizona Supreme Court sided with State Farm, holding that when two or more named insureds jointly procure a policy, such as spouses who together purchase household auto coverage, they act as a single purchasing unit and are "one insured" for anti-stacking purposes under A.R.S. § 20-259.01(H). The court's reasoning tracked the recurring language in both the statute and the policies themselves: coverage "purchased by one insured" is capped as a unit, regardless of how many named drivers or vehicles that policy covers, and regardless of who actually paid the premium or how community property is characterized between spouses. Applying that reading, the court let State Farm cap the claimant's total UIM recovery at the two policies it had already paid.

What the Law Actually Says

Arizona does not require drivers to carry UM/UIM coverage, but insurers must offer it in writing under A.R.S. § 20-259.01, and a driver can accept coverage up to the same limits as their liability policy or reject it outright. The statute allows insurers to include anti-stacking provisions that prevent a claimant from combining UM/UIM limits across every policy that happens to cover them, so long as the provisions are consistent with the statute's own terms, including the "one insured" language the Supreme Court applied in Balzan.

This matters because Arizona is a pure comparative-negligence, at-fault state (see the Arizona car accident laws page for the full framework), where an injured driver's practical recovery is often limited by the at-fault driver's insurance limits. UM/UIM coverage exists precisely to fill that gap when the at-fault driver is uninsured or does not carry enough coverage, including in hit-and-run cases where the responsible driver cannot be identified or located at all. Balzan narrows how far that gap-filling coverage can stretch when a household insures several vehicles under policies bought jointly rather than individually, a distinction that also matters for truck accident claims and other cases involving severely underinsured at-fault parties. For the general framework of how car accident claims work across states, see car accident laws by state.

Analysis: Why This Matters

The following is analysis from the Recording Law Editorial Team. Balzan resolves a real ambiguity in how Arizona's anti-stacking statute treats households that insure multiple vehicles under one insurer, an increasingly common arrangement as families consolidate policies for multi-car discounts. The court's focus on who "procured" the policy, rather than who is named as a driver or who pays the premium, means that a family's decision to buy several vehicles' coverage jointly, rather than through separate individually purchased policies, can meaningfully cap the UIM benefits available after a catastrophic crash.

The ruling does not eliminate UM/UIM stacking in Arizona altogether; it interprets specific policy language tied to how coverage was purchased. Households or individuals whose policies were purchased separately by different named insureds, rather than jointly, may reach a different result under the same statute. The decision is also specific to State Farm's policy wording and this insurer's use of the "one insured" phrase; other carriers' anti-stacking clauses could be phrased differently and analyzed on their own terms.

How This Affects You

If you or a family member carries UM/UIM coverage in Arizona, courts have generally looked to exactly who is listed as the purchasing insured on each policy and how the anti-stacking language in that policy is worded, not simply how many vehicles or premiums are involved. Anyone relying on UM/UIM coverage to cover a severe injury, especially where multiple household policies are in play, should review the actual policy declarations and anti-stacking clauses with a licensed Arizona attorney before assuming a specific dollar amount will be available.

This is general legal information, not legal advice. It covers Arizona and reflects sources verified on July 8, 2026. Laws change and this story is developing; consult a lawyer licensed in your jurisdiction about your specific situation.

Related articles

• Arizona Car Accident Laws: Fault, Insurance, and Your Claim
• Car Accident Laws by State
• Arizona Hit and Run Laws
• Truck Accident Laws in Arizona

Last updated: 2026-07-08. This is a developing story; details verified as of 2026-07-08.

Frequently Asked Questions

What is underinsured motorist (UIM) coverage?

UIM coverage pays a policyholder when the at-fault driver's own liability insurance is not enough to cover the injured person's damages. In Arizona it is optional but insurers must offer it in writing under A.R.S. § 20-259.01.

What does it mean to "stack" UIM coverage?

Stacking means combining UIM limits from more than one applicable policy, for example a driver's own policy plus a household policy on another vehicle, to reach a higher total payout than either policy alone provides.

What did the Arizona Supreme Court decide in State Farm v. Balzan?

On July 6, 2026, in No. CV-24-0140-PR, the court held that named insureds who jointly purchase auto policies, such as spouses buying household coverage together, count as "one insured" under A.R.S. § 20-259.01(H), letting State Farm limit the claimant's UIM recovery to two of five available policies.

How much money was at stake in the Balzan case?

The claimant's own policy and one household policy each carried $250,000 in per-person UIM coverage. State Farm paid both, $500,000 total, but denied stacking onto three more household policies with the same limits.

Does this ruling mean UIM stacking is banned in Arizona?

No. The decision interprets specific anti-stacking language tied to jointly purchased policies. Stacking outcomes can differ depending on how a policy was purchased and how an insurer's specific anti-stacking clause is worded.

Is UM/UIM coverage required in Arizona?

No. Arizona insurers must offer UM/UIM coverage in writing under A.R.S. § 20-259.01, but a driver may reject it. Only liability coverage of 25/50/15 is mandatory under A.R.S. § 28-4009.

Who does the Balzan ruling affect?

It most directly affects Arizona households insuring multiple vehicles through State Farm policies that spouses or other co-insureds purchased jointly, since the ruling turns on how coverage was procured, not just how many policies exist.