Probably not. Private foundations may still be subject to taxes on investment earnings and undistributed minimum grant allocations. All 501(c)(3) organizations may be subject to taxes on "unrelated business income." 501(c)(3) organizations that have employees are subject to federal and state payroll taxes. Additionally, some states do not exempt 501(c)(3) organizations from sales and/or property taxes. It is important for the organization to know what is required in its state and locality.