Do you know your property's APN? If yes, skip to Step 2. If not, go to the Assessor's Office website and search for your address.
In the search results page, find your property and the first column is the APN.
Go to the Maricopa County Treasurer's Office website and do a Parcel Search using the APN.
On the Parcel Details page, in the Tax Due section, select the Tax Year Details link.
Find the section for Special Tax Districts to see a list of any and all Districts you may be in.