Aggregate Tax Benefit Defined

(1) For purposes of Section 507(c)(1), the aggregate tax benefit resulting from the

Section 501(c)(3) status of a private foundation is the sum of:

a. The aggregate increases in tax under Chapters 1, 11, and 12 (or the

corresponding provisions of prior law) that all substantial contributors to the foundation would have incurred if their contributions had not been deductible after February 28, 1913.

b. The aggregate increases in tax under Chapter 1 (or the corresponding

provisions of prior law) that the private foundation would have incurred for taxable years beginning after December 31, 1912, had it not been exempt from tax under Section 501(a) (or the corresponding provisions of prior law); and, in the case of a trust, if deductions under Section 642(c) (or the corresponding provision of prior law) had been limited to 20% of the taxable income of the trust (computed without benefit of Section 642(c) but with the benefit of Section 170(b)(1)(A)).

c. The amount succeeded to from transferors under Regs. 1.507-3(a) and

Section 507(b)(2).

d. Interest on the increases in tax determined in (a), (b), and (c) above from

the first day on which each such increase would have been due and payable to the date on which the organization ceases to be a private foundation. See Treas. Reg. 1.507-5(a).

(2) In computing the amount of the aggregate increases in tax, all deduction

benefits attributable to a particular contribution shall be included. See Treas. Reg. 1.507-5(b).