What an STO is, in one paragraph
A School Tuition Organization is a nonprofit certified by the state to collect gifts that donors then claim as an Arizona tax credit. The STO turns those gifts into scholarships for students at the private schools on its list. Joint filers can send $1,570 through the original credit and $1,561 more through the switcher credit for tax year 2026, with an April 15, 2027 cutoff for 2026 gifts. None of that money goes to the donor's own children; swapping donations between families is prohibited.
The STOs Valley families see most
In our directory, IBE, APSTO, School Choice Arizona and APESF list the most Phoenix-area schools, because they serve schools of every kind. ACSTO, the oldest and largest STO by cumulative giving, and AZTO serve Christian schools. Catholic Education Arizona is the Diocese of Phoenix's STO. The Jewish Tuition Organization serves the Valley's Jewish day schools, Greater Arizona Inc. supports Muslim students, and the Arizona Episcopal Schools Foundation serves a handful of Episcopal schools. The table below shows how many Valley schools each STO lists.
Applying to more than one
Families apply to each STO separately, and nothing stops you from applying to every STO that lists your child's school. Each sets its own calendar: ACSTO opens next-year applications Feb 3 and awards four times a year; IBE opens Feb 1; Catholic Education Arizona runs rounds through FACTS that began Feb 1 for 2026-27. Being on a list means the school can receive that STO's scholarships, not that your child will get one.
When the STO route makes more sense than the ESA
Because the ESA and STO scholarships cannot fund the same child in the same year, the STO route is a deliberate choice. It tends to make sense when a family has a large, established STO award at a high-tuition school, when relatives give steadily to the school's STO, or when a family wants to avoid the ESA's quarterly spending reports. Leaving the ESA is itself a qualifying condition for switcher and low-income corporate scholarships, so a family can move from one path to the other at the start of a school year.
Asking family to give
Grandparents and friends who owe Arizona income tax can send their credit to the STO your school uses. STOs weigh family need and the student's story, and some consider donor recommendations, but by law they cannot award a scholarship only because a donor asked. Treat outside giving as something that improves your chances, not a guarantee.
STOs and how many Valley schools each lists
| School Tuition Organization | Phoenix-area schools on its list | Notes |
|---|---|---|
| IBE | 191 | Tucson-based multi-school STO; lists more Valley schools than any other |
| APSTO | 158 | Scottsdale-based; K-12 students at qualified private schools of any kind |
| School Choice Arizona | 140 | Chandler-based; mostly low-income corporate scholarships |
| APESF | 87 | Multi-school "best fit" STO operating since 1999 |
| ACSTO | 73 | Christian schools; the largest STO by money raised since 1998 |
| Catholic Education Arizona | 30 | The Diocese of Phoenix STO; applications through FACTS |
| Jewish Tuition Organization | 10 | Phoenix-based; Jewish day schools and yeshivas |
| AZTO | 5 | Christian schools; (602) 295-3033 |
| Students First Foundation | 3 | Mainly corporate scholarships; weighs merit and need |
| Arizona Episcopal Schools Foundation | 3 | Episcopal member schools such as All Saints' and Christ Church |
| Greater Arizona | 3 | Supports Muslim students at Islamic schools and programs |
Counts schools in our directory that appear on each STO's published school list (Oct 2026). A school on a list can receive scholarships through that STO; an award is never guaranteed.
Next step
Ready to find out which funding fits? Take the short funding check and a School Funding Advisor will call to go over the ESA, STO and school-aid options for your child, with the dates that matter.