A disqualified person is any person who was in a position to exercise substantial influence over the affairs of the applicable tax-exempt organization at any time during the lookback period. It is not necessary that the person actually exercise substantial influence, only that the person be in a position to do so.
For this purpose, donors and donor advisors with respect to a donor advised fund are treated as disqualified persons with respect to transactions with the fund. Moreover, the entire amount involved paid to such persons is treated as an excess benefit. Finally, a person who is able to exercise substantial influence over a section 509(a)(3) supporting organization is a disqualified person not only with respect to that organization, but also with respect to the organization(s) the supporting organization is organized and operated to benefit.
Family members of the disqualified person and entities controlled by the disqualified person are also disqualified persons. For this purpose, the term control is defined as owning more than 35 percent of the voting power of a corporation, more than 35 percent of the profits interest in a partnership, or more than 35 percent of the beneficial interest in a trust.