QSBS, Trusts, and the $15 Million Exclusion: A 2026 Estate Planning Guide for Pre-Liquidity Tech Founders
QSBS is the single most powerful federal tax break available to early employees and founders of qualifying startups. The One Big Beautiful Bill Act, signed July 4, 2025, expanded the benefit materially. For couples holding qualifying stock in companies like SpaceX, OpenAI, or Anthropic, understanding the new QSBS rules and how trusts can multiply the exclusion is worth a careful read. This is the 2026 guide.
Key takeaways
- Section 1202 of the Internal Revenue Code lets shareholders exclude federal capital gains tax on Qualified Small Business Stock (QSBS). For stock acquired on or after July 4, 2025, the per-issuer exclusion cap is $15 million or 10 times the taxpayer's adjusted basis, whichever is greater.
- The OBBB Act added a tiered holding period. A 3-year hold qualifies for 50% exclusion, a 4-year hold for 75%, and a 5-year hold for the full 100% exclusion. Stock acquired before July 4, 2025 keeps the prior rules (5-year hold required, $10 million cap).
- The aggregate gross asset threshold rose to $75 million (from $50 million) for stock acquired on or after July 4, 2025. Both the $15 million cap and the $75 million threshold are indexed for inflation starting 2027.
- Trust stacking can multiply the exclusion. Each non-grantor trust funded with QSBS-eligible stock can claim its own $15 million per-issuer cap. A founder with significant qualifying stock can spread shares across multiple irrevocable trusts before the event and multiply the federal capital gains exclusion accordingly.
- Neptune's standard $2,500 estate plan does not handle QSBS stacking. The standard plan covers the revocable trust, wills, and core documents that every couple needs. For QSBS trust structuring, the right move is a tax-focused trusts and estates specialist. Neptune can refer.
What qualifies as QSBS
For stock to qualify as QSBS under Section 1202, several conditions need to be met:
- The stock must be issued by a domestic C corporation (not an S corp, not a partnership, not an LLC).
- The stock must be acquired at original issuance, either directly from the corporation or through certain exempt transfers. Stock bought on the secondary market generally does not qualify.
- The corporation must meet an active business requirement: at least 80% of its assets must be used in the active conduct of a qualified trade or business.
- The corporation's aggregate gross assets must have been at or below the threshold ($50 million for pre-July 4, 2025 stock, $75 million for post) immediately before and after the issuance.
- Certain industries are excluded: financial services, professional services, hospitality, farming, mineral extraction, and a few others. Technology companies generally qualify.
For SpaceX, OpenAI, and Anthropic specifically, employee stock options exercised when the company was below the gross asset threshold can qualify. Restricted stock units (RSUs) that vested and were settled in stock can qualify if the original issuance was at a time the company met the gross asset test. Stock bought on the secondary market (some tender offers) does not qualify as QSBS for the purchaser. For a fuller overview of the OBBB Act changes to QSBS, the Mintz client alert walks through the statute as amended.
How trust stacking multiplies the exclusion
The $15 million exclusion cap applies per taxpayer per issuer. A non-grantor irrevocable trust is a separate taxpayer for federal income tax purposes. So a founder who funds multiple non-grantor trusts with QSBS-eligible stock can claim a $15 million exclusion on each one, separately. The technique is sometimes called QSBS stacking, and it can substantially increase the gain a family excludes from federal tax.
In practice, this works as follows. Before the liquidity event, the founder gifts a portion of QSBS-eligible stock to one non-grantor trust for the benefit of, say, the founder's spouse and children. Then gifts another portion to a second non-grantor trust for a different beneficiary set. Each gift uses lifetime federal exemption (under the $30 million married couple cap) at the pre-event valuation. After the trusts hold the stock for the required period and sell at the liquidity event, each trust separately excludes up to $15 million of gain.
The mechanics require careful drafting. The trusts must be properly funded well before any sale is contemplated. The stock must remain qualifying through the holding period. And the trust structure must avoid grantor trust treatment, which would consolidate the exclusion back at the founder level. The IRS may aggregate certain trusts with substantially the same grantor and primary beneficiaries under the multiple-trust rules in Section 643(f) where the principal purpose is tax avoidance, so each trust needs to be drafted with meaningful differences and an independent reason for existing.
When QSBS stacking is and isn't worth it
Trust stacking is worth the structuring cost when:
- The founder holds substantially more than $15 million of QSBS-eligible stock.
- The liquidity event is far enough out that the trust funding and holding period work.
- The federal capital gains tax savings outweigh the trust setup, ongoing trustee fees, and complexity.
Trust stacking is not the right answer when:
- The founder's total QSBS gain is at or below the standard $15 million cap.
- The liquidity event is imminent, and there is not enough time to set up the trusts properly.
- The founder needs continued access to the funded equity for personal liquidity, which a non-grantor irrevocable trust restricts.
For the founder who is below the single $15 million cap, the standard plan plus a 5-year hold captures the full benefit without trust structuring. Neptune's $2,500 estate plan handles the standard plan (the revocable trust and core document set). The QSBS hold itself is just disciplined timing. Trust stacking is an advanced overlay on top of that foundation, and a SLAT structure is the most common version of the irrevocable vehicle couples use here.
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Frequently asked questions
Does QSBS apply to RSUs at SpaceX, OpenAI, or Anthropic?
RSUs that vest and are settled in stock can qualify as QSBS if the company met the gross asset test at the time of original issuance and the other Section 1202 requirements are met. The analysis is fact-specific. A tax-focused trusts and estates attorney can evaluate your specific grant history and confirm what qualifies.
What happens to stock acquired before July 4, 2025?
Stock acquired before that date follows the prior rules: $10 million per-issuer cap (or 10x basis), 5-year holding period required for the full 100% exclusion, $50 million gross asset test. There is no retroactive application of the OBBB Act's improvements to pre-July 2025 stock.
Does Neptune handle QSBS trust stacking?
No. Neptune's standard $2,500 estate plan covers the revocable trust, pour-over wills, healthcare directives, powers of attorney, and guardian designations that every couple needs. QSBS trust stacking and other tax-driven structures (SLATs, GRATs, dynasty trusts) require a tax-focused trusts and estates specialist. Neptune is upfront about scope and can refer to specialists.
What if I'm not sure my stock qualifies?
That is the right question to ask before doing any structuring. A tax-focused trusts and estates attorney can review your grant documents, the company's QSBS status at the relevant dates, and your holding period to confirm what qualifies. Don't structure around QSBS unless you have confirmed eligibility.