The following agencies provide assistance with child support issues:

The Self-Service Center in Maricopa County has any form you may need relative to child support and other domestic relations cases: Self Support Center, 101 West Jefferson, Phoenix, Arizona 85003 or http://www.maricopa.gov/supcrt/ssc/sschome.html

The Child Support Enforcement Agency in Arizona is:
The Department of Economic Security, Division of Child Support Enforcement (DCSE)
The DCSE Customer Service Hot Line number is: 602/252-4045
https://www.azdes.gov/dcse/

CSE office locations and phone numbers are also available on the DCSE web site at:  https://www.azdes.gov/publicApps/do/FindOfficeForm where you can apply for services, including: locating absent parents, establishing paternity, establishing child support or enforcing an existing order.