Example. G transfers property in trust with the ordinary income payable to University C (which qualifies under section 170(b)(1)(A)(ii)) for 3 years, and then to his son, B, for 5 years. At the expiration of the term the trust reverts to G. G is not taxed under section 673 of the trust income payable to University C for the first 3 years because of the application of section 673(b). However, he is taxed on income for the next 5 years because he has a reversionary interest which will take effect within 10 years commencing with the date of the transfer. On the other hand, if the income were payable to University C for 3 years and then to R for 7 years so that the trust corpus would not be returned to G within 10 years, G would not be taxable under section 673 on income payable to University C and to B during any part of the term.
26 C.F.R. §1.673(b)-1