AZ SB1434

Divides Maricopa County into four separate counties: a reduced Maricopa County (centered on Phoenix, Glendale, Tempe, and Chandler), Hohokam County (Mesa and Chandler area), Mogollon County (northern Phoenix, Scottsdale, and Paradise Valley area), and O'odham County (western portion including Peoria, Surprise, and Goodyear)

Establishes a three-year transition period during which an intercounty oversight and accountability board, composed of the chairpersons of each new county's board of supervisors, will manage shared services and intergovernmental agreements

Requires special elections within 120 days after the effective date to elect new boards of supervisors for all four counties, with supervisors initially elected at-large and later by district

Mandates shared use agreements for existing capital assets up to ten years and requires intergovernmental agreements for community college operations for at least ten years

Takes effect December 31, 2026, with new county supervisors to be sworn in by June 15, 2027