Property taxes in Maricopa County are established by the Assessor’s Office, currently headed by Paul D. Petersen.
The job of the Assessor is to identify all taxable property in Maricopa County and to determine ownership. He establishes the value for all property that is subject to taxation and lists it on the assessment roll, taking into account all exemptions. The Assessor does not compute or collect property tax. That is the job of the County Treasurer. He also doesn’t establish property tax laws. That is the job of the legislators.
The Assessed Value of your property begins with an appraisal of your home, but your appraiser does nothing to determine property taxes.
This helpful video from the Maricopa County Assessor’s Office makes it easy to understand.