Uninsured vs. Underinsured Motorist Coverage in Arizona

By the FigureMyTax Editorial Team · How we calculate

Arizona has two coverages that apply to different situations: UM when the at-fault vehicle has no policy meeting the minimum limits, and UIM when the sum of all applicable liability limits is less than your total damages.

Uninsured motorist (UM) coverage

Under A.R.S. 20-259.01(E), UM covers damages for bodily injury or death when the vehicle that caused them is not insured by a policy with at least the limits in A.R.S. 28-4009. For policies issued or renewed since July 1, 2020, those minimums are $25,000 per person, $50,000 per accident and $15,000 for property damage. A vehicle whose liability insurer cannot pay because of insolvency also counts as uninsured (subsection (D)).

Underinsured motorist (UIM) coverage

Under subsection (G), UIM applies if the sum of the limits under all bodily injury liability policies applicable at the time of the accident is less than your total damages, and to the extent damages exceed those limits, UIM applies to the difference. Subsection (F) adds that a payment under the at-fault vehicle's liability coverage, up to its limits, precludes UM based on that insured driver's fault, which is why a driver with a compliant policy leads to a UIM claim, not a UM claim.

They do not overlap

Subsection (H) says the two coverages are separate and distinct and apply to different accident situations, and that UIM does not cover a claim against an uninsured motorist in addition to any applicable UM. See how subsection (H) also governs stacking.

Insurers must offer both

Every insurer writing auto liability policies must offer UM and UIM in limits not less than the policy's liability limits, on a form approved by the director, unless the named insured buys that amount. The named insured may buy less, but not below the limits in 28-4009, and the declarations page is the final expression of the decision to buy or reject each coverage.

Unidentified drivers

If you make a UM or UIM claim for an accident involving an unidentified vehicle with no physical contact, you must provide corroboration that it caused the accident: additional and confirming testimony, fact or evidence that strengthens your account (subsection (M)).

UIM is not capped by the liability limit

In Franklin v. CSAA General Insurance Co. (2023), the Arizona Supreme Court held that subsection (B) does not limit UIM coverage to the policy's liability limits. Then run your case through the Arizona UM/UIM stacking calculator and read how stacking raises the ceiling.

This is general information, not legal advice, and the state comparisons above are illustrative, not an exhaustive survey. Confirm how Arizona's rules apply to your specific case with a licensed Arizona attorney.