Why does Private Foundation status matter to a donor?

The tax deduction benefits of donating to Private Foundations are generally more limited than for other charities.

Donors generally can deduct up to 50% of their adjusted gross incomes for contributions to Section 501(c)(3) organizations.
Many Private Foundations are Section 501(c)(3) organizations. Donors, however, generally can deduct only up to 20% of their adjusted gross income for contributions to Private Foundations.

The CharityCheck Report for an organization shows whether or not it is a Private Foundation. See the Tax Status section of the Report.