University of Arizona has a neuropsych program. Department of Neuroscience
Gould-Simpson Bldg.
Tucson, AZ 85721
(520) 621-6627
One of the staff may know who is in practice in Tucson.

You could also try Banner's (associated with University of Arizona) Alzheimer Institute at 2626 E River Rd. Tucson, AZ 85718 (520) 694-7021. They may have a list of Medicare approved neuropsych PhDs in practice.

The mental health unit at the Veteran's administration on 6th Ave has a neuropsych person on staff if your spouse is a veteran.

Also check with the Area Agency on Aging Pima County