QSBS Stacking and Potential Treasury Guidance: Why Good Planning Withstands Scrutiny

That concern became more concrete in May 2026, when Treasury Assistant Secretary for Tax Policy Kenneth Kies reportedly told a DC tax conference that Treasury was “taking a close look” at QSBS stacking. According to reporting, Kies indicated that Treasury was focused on investors who go beyond the ordinary one-trust-per-family-member planning model, although the timing and scope of any guidance remain uncertain.

Stacking generally refers to transferring QSBS to separate taxpayers, including non-grantor trusts, so that each taxpayer may potentially use its own Section 1202 exclusion. Because the exclusion cap applies on a per-taxpayer basis, properly structured transfers can increase the aggregate amount of gain eligible for exclusion. Section 1202 also expressly permits gifted QSBS to retain its favorable character in the recipient’s hands, including the donor’s holding period. Following recent legislation, the exclusion cap was increased from $10 million to $15 million for certain QSBS, while the statutory gift-transfer rule remains central to legitimate planning.

Any forthcoming guidance is likely to emphasize guardrails that careful planners have already taken into account for years. Good QSBS planning has not depended on duplicative identical trusts, last-minute transfers or beneficiaries with no meaningful relationship to the founder. Instead, prudent structures have focused on separate trusts for separate beneficiaries, genuine donative intent, real non-tax estate planning purposes and transfers made well before a sale process is underway.

Those guardrails matter because the IRS already has tools to challenge abusive structures. Section 643(f) permits multiple trusts to be treated as one where they have substantially the same grantor and primary beneficiary and a principal purpose of tax avoidance. The assignment-of-income doctrine may also apply where shares are transferred after the economic gain has effectively been earned.

For founders, the takeaway is practical rather than alarmist. Treasury may issue guidance, and that guidance may target aggressive stacking. But well-designed planning should already reflect the principles likely to be emphasized: different beneficiaries, real economic separation, documented estate planning purposes, early transfers and no retained benefit for the donor.

QSBS stacking can remain an important planning tool. The key is ensuring the structure looks like family and estate planning first—not a tax shelter assembled on the eve of an exit.