Ariz. Rev. Stat. § 12-555
A. An insurer is not liable for uninsured motorist coverage benefits unless the person making the claim gives written notice to the insurer of the person's intent to pursue the claim against the uninsured motorist portion of a motor vehicle policy within three years after the date of the accident that caused the bodily injury, except that a person may make an uninsured motorist claim within three years after the earliest of the following:
C. If settlement of an uninsured or underinsured motorist claim is not reached: