Hi ian -
We don't have a formal answer for you on that. There are certainly thousands of PTOs that are independent 501c3s. But whether that is 4,000 or 14,000 or 24,000 -- we don't know.
From our research, many of those who aren't formally registered likely fall under nonprofit status anyway by virtue of either a) how they operate; or b) being a part of/committee of a nonprofit school.
Tim
- Rockne
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