http://www.kenniffonline.com/profits-for-purpose/

How do I know if my non profit is a private foundation or public charity?
It was created as non profit for the purpose of giving grants to medical residents and fellows who intend to finish a specialty of high demand and need in Puerto Rico. The money will come from fund raising.
The distinction between a private foundation and a public charity has mainly to do with the plurality of its funding sources. It sounds as if you are working with a public charity. The prototypical (but not only) private foundation is a family foundation, funded mostly by a single wealthy individual/family.
There are other distinctions which flow from that main one. To qualify as a public charity you would have to meet a “Public Support Test” based on an average three-years’ worth of funding.
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