Two coverages on your own auto policy decide more Arizona injury claims than almost anything the other driver carries. They sound alike, they sit next to each other on the declarations page, and they do different jobs.
What uninsured motorist coverage does
UM coverage responds when the driver who caused the crash has no liability insurance at all. It commonly comes up in hit-and-run crashes, where the at-fault driver is never identified, and in crashes with drivers who let their coverage lapse. Instead of chasing a person with no policy behind them, the claim is made under your own coverage — which is exactly what it was purchased for.
What underinsured motorist coverage does
UIM coverage responds to a different problem: the at-fault driver has insurance, but the limits are too small for the injuries. A serious injury can pass a minimum-limits policy quickly. When that happens, UIM coverage can pay the difference between what the at-fault driver's policy provides and what your own UIM limits allow.
Why Arizona law makes both worth checking
Under A.R.S. § 20-259.01, every insurer writing auto liability coverage in Arizona must offer UM and UIM coverage — a policyholder who doesn't have them generally declined them at some point, often without remembering it. The declarations page answers it in one line. Because these are coverages you already paid for, reviewing them is a standard part of evaluating any serious crash, and it's a fair question to ask any firm whether that review happens on every case.
What a claim under your own policy looks like
A UM or UIM claim is still an injury claim: it has to be documented, valued, and supported the same way a claim against the other driver would be. Arizona's usual rules apply — most injury claims must generally be filed within two years, and partial fault reduces a claim by percentage rather than ending it. The difference is who pays, not what has to be proven.
Saguaro Injury Law reviews UM/UIM coverage on every case, in English and Spanish, and the free UM/UIM Coverage Check on this site is a two-minute way to see what your own policy may provide. A free consultation is available any hour: (602) 217-0000.