What Is QSBS Stacking? Definition, How It Works and Examples

The cap in Section 1202(b) is written per taxpayer and per issuer, the company that issued the stock. Each taxpayer may exclude gain on one company’s stock up to the greater of two amounts: the dollar limit or ten times their basis in the shares sold. Basis is, roughly, what was paid for the shares. The dollar limit is cumulative. It is reduced by what that taxpayer excluded on the same company in earlier years. A second taxpayer has a cap of its own.

The bridge is Section 1202(h). Stock transferred by gift, at death or by certain partnership distributions keeps its status. The recipient is treated as having acquired it the way the donor did. The recipient is also treated as having held it for the donor’s holding period. Without that rule, the recipient would fail the original-issue test, which requires getting the shares directly from the company. That test is covered in QSBS requirements.

The basis carries over with the gift. Founder stock has almost no basis, so the ten-times-basis prong is worth little in anyone’s hands. That is why stacking multiplies the dollar limit.

What Stacking Does Not Do

Marriage does not double the cap. On a joint return, the excluded gain is allocated equally between the spouses for later years. On separate returns, each spouse gets half: $5 million for stock acquired on or before July 4, 2025, and half of the $15 million figure for later stock. A sale of shares to a relative or a trust is not a gift, so QSBS status does not carry over.

A QSBS trust is a trust that receives qualified stock by gift and is its own taxpayer, so it has its own Section 1202 cap. That last condition is the one that matters. A grantor trust is ignored for income tax. Under Section 671, its income is taxed to the grantor, the person who funded it. So its gain sits under the grantor’s cap and adds nothing. Only a non-grantor trust counts separately. In that kind of trust, the grantor has given up the powers that make it a grantor trust.

A non-grantor trust pays its own income tax at compressed trust rates, which reach the top bracket at a much lower income. Gain above its cap is taxed in the trust unless it is distributed. A trust that keeps net investment income pays the 3.8% surtax above $16,000 in 2026. Gain excluded under Section 1202, however, is not net investment income at all. See NIIT and IRS Topic 559.

QSBS trust stacking uses several non-grantor trusts, each holding part of the stock and each claiming a cap. The limit is Section 643(f). It treats two or more trusts as one if they have substantially the same grantor and substantially the same primary beneficiary, the person the trust mainly serves. A principal purpose of avoiding income tax must also be present. For this rule, a husband and wife are one person.

In practice, stacking trusts are judged one beneficiary at a time. Several trusts for the same child, set up by the same parents, risk being collapsed into one trust with one cap. Separate trusts for different children are a different set of facts. Section 1202(k) also gives the Treasury power to write regulations against avoidance through split-ups, shell corporations and partnerships.

Trust is a grantor trust

Its gain is the grantor’s and shares the grantor’s cap. Confirm non-grantor status when the trust is drafted. Checking afterward is too late.

Trusts share grantor and beneficiary

Section 643(f) can treat them as one. The usual answer is one trust per distinct primary beneficiary.

Gift made after the sale is agreed

By then the gain has, in substance, already been earned. That invites an assignment-of-income challenge: the argument that income stays taxable to the person who earned it. Timing is part of the plan.

Shares sold to the trust

A purchase is not a gift, so the trust fails original issue. Only gifts, bequests (assets left by will) and qualifying partnership distributions carry status.

Gift value larger than planned

A late gift is valued near the deal price and uses more of the $15M lifetime exclusion. Earlier gifts move more value per dollar of exclusion.

A founder buys common stock at formation in September 2025 for $2,000. The company is a Delaware C corporation that passes every Section 1202 test. Early on, while the shares are worth little, the founder gives a quarter of them to each of two non-grantor trusts, one for each child. Six years later, the company is sold and the whole block fetches $60 million.

The difference is the size of two extra caps, taxed at 23.8%. Federal tax falls from $10.71 million to $3.57 million, or by two-thirds. That holds only if every assumption in the caption holds. The founder also no longer owns half the stock. The trusts own it, under trustees, for the children, and that outlasts the tax saving.

• Using a grantor trustMany estate-planning trusts are grantor trusts by design. They do not create a second cap.
• Several trusts for one beneficiarySame grantor, same beneficiary and a tax purpose is the set of facts Section 643(f) targets.
• Waiting for the term sheetA term sheet sets out the price and terms of a sale. A gift made as a sale closes is worth more for gift tax. It is also weaker against an assignment-of-income argument.
• Stacking stock that does not qualifyA gift carries status but cannot create it. If the shares fail Section 1202 in the donor’s hands, every trust fails too.
• Counting on the spouseSpouses share a cap on a joint return and split it on separate returns.

QSBS stacking

Spreading qualified stock across several taxpayers by gift so each can claim a Section 1202 cap on the same company.

Per-issuer cap

The most gain one taxpayer may exclude on one company’s stock: the greater of $15M ($10M for older stock) or ten times basis.

Basis

What was paid for the shares, adjusted for tax. It carries over to the recipient of a gift.

Section 1202(h)

The rule that lets stock transferred by gift, at death or by certain partnership distributions keep its QSBS status and holding period.

Non-grantor trust

A trust that is its own income taxpayer, because the grantor has not kept the powers that make it a grantor trust.

Grantor trust

A trust whose income is taxed to the person who funded it. For QSBS it shares that person’s cap.

Section 643(f)

The rule that treats multiple trusts with the same grantor and primary beneficiary, set up mainly to avoid tax, as one.

QSBS

Qualified small business stock under Section 1202, whose gain can be partly or fully excluded.

Related: what is QSBS, QSBS requirements, QSBS attestation letter and family offices, where these structures are usually run.

Every rule and figure was checked against the US Code and the IRS on October 2, 2026. They reflect federal law as amended on July 4, 2025. The worked example is illustrative arithmetic with no client or market data behind it. Gift, estate and state tax are not covered beyond the figures cited.