Qualified Small Business Stock

IRC §1202 is the most valuable single provision in the code for a founder, because it can take the tax on a business sale to zero. Stock that qualifies as qualified small business stock (QSBS) is eligible for an exclusion of capital gain on sale — and OBBBA expanded the provision substantially.

It is also the cleanest example in this book of what section “The Structure of Luck” calls Chance III. Nothing about a successful exit is luck in the ordinary sense, but the option to take that exit tax-free is created years earlier, at incorporation, by a founder who already knew this section existed. There is no way to buy it back afterward: the wrong entity, the wrong issuance, or a secondary purchase instead of original issue closes the door permanently, and the door closes quietly, at a moment when the company has no value and nobody is thinking about capital gains. The founders who miss it were not unlucky. They were unprepared at the one moment preparation was worth eight figures.

The qualifying conditions are strict and must all hold:

• The stock is issued by a domestic C-corporation. An LLC or S-corporation cannot issue QSBS. A founder who began as an LLC must convert to a C-corporation — generally a tax-free transaction under IRC §351 — and the QSBS holding clock starts only at that conversion.
• You acquired the stock at original issue, in exchange for money, property, or services — not on the secondary market.
• The corporation’s aggregate gross assets did not exceed $75 million at any time before, or immediately after, the stock was issued. (This ceiling was $50 million before OBBBA, and is indexed for inflation from 2027.)
• The corporation runs an active qualified business. The service fields excluded from the IRC §199A deduction are excluded here too, and IRC §1202(e)(3) adds engineering and architecture — which do get the QBI deduction — along with banking, insurance, financing, leasing, investing, farming, mining, and hospitality. An engineering firm can take §199A every year and still never issue QSBS.

For stock acquired after July 4, 2025, OBBBA introduced a tiered holding period and raised the cap:

Held 3 to 4 years

50% of the gain is excluded.

Held 4 to 5 years

75% is excluded.

Held 5 years or more

100% is excluded.

The per-issuer exclusion is capped at the greater of $15 million (up from $10 million, and indexed from 2027) or 10 times your basis in the stock. The partial tiers carry hidden costs. First, the non-excluded portion of QSBS gain is taxed at a 28% rate, not the ordinary 20% long-term rate, and it carries the 3.8% NIIT. And IRC §57(a)(7), “Items of tax preference” makes 7% of the excluded gain an alternative-minimum-tax preference item on the partial tiers — the full five-year 100% exclusion is exempt from that preference, which is what makes it qualitatively different, not merely larger. Put the three tiers on a common footing:

Against a 23.8% baseline on an ordinary long-term gain, three years already saves most of the tax. But the last twelve months of a five-year hold are worth 7.95 points and the removal of an AMT adjustment — rarely a reason to sell at four years and eleven months. Stock acquired before the OBBBA date keeps the old rules: $10 million cap, $50 million asset test, and a flat five-year hold for 100%.

Two more clocks start later than founders assume. Founder shares are almost always subject to vesting, and without a timely IRC §83(b) election — thirty days from the grant, no extensions — each tranche is treated as acquired when it vests, so the five years run from every vesting date instead of the day you incorporated (section “Restricted Stock: RSUs, RSAs, and the 83(b) Election”). File it the week the stock is issued; the tax on a founder’s stock at formation is trivial and the holding-period consequence is not. Redemptions are the other clock-killer. Under IRC §1202(c)(3), stock is not QSBS if the corporation bought back stock from you or a related person within two years before or after it issued yours, or made “significant” redemptions from anyone — more than 5% of the company’s stock by value — within a year on either side. Buying out a departing co-founder in year one, the most ordinary event in a startup’s life, can strip QSBS status from every share issued in the surrounding window; Treas. Reg. §1.1202-2 carves out repurchases on death, disability, divorce, and termination of employment, plus a de minimis threshold, and nothing else. Structure the departure as a cross-purchase between founders instead of a corporate redemption where the shares matter.

One trap deserves a flag before you start counting years. If early capital came into the company through SAFEs or convertible notes — the default for venture-backed startups — the holding clock may not start when the instrument was signed. Whether a SAFE counts as stock for IRC §1202, and therefore whether its holding period runs from issuance or only from its later conversion into preferred stock, is unsettled. A founder or early investor who assumes the clock started at the SAFE can miscalculate the exit by a year or more — section “QSBS and Section 1202” works through the question.

Because the cap is measured per taxpayer, founders with gains well above $15 million sometimes multiply it by gifting QSBS to irrevocable non-grantor trusts for family members — each trust is a separate taxpayer with its own cap. “Stacking” is legitimate but advanced: it requires properly structured non-grantor trusts and coordination with the estate plan (section “Estate planning”), and it should not be attempted without counsel. Note also that some states, California among them, do not conform to IRC §1202 — the exclusion shelters federal tax only, and state tax still applies. The investor’s side of QSBS, including the IRC §1045 rollover that preserves the clock when one qualifying stock is swapped for another, is covered in section “QSBS and Section 1202”.

The loss side has its own section number. IRC §1202 rewards the exit that works; IRC §1244, “Losses on small business stock” cushions the one that does not. Original-issue stock of a corporation capitalized with $1 million or less qualifies for ordinary loss treatment — up to $50,000 a year ($100,000 on a joint return) when the company fails or the stock is sold at a loss — instead of the $3,000-a-year capital-loss grind. It is automatic when the conditions hold, costs nothing to preserve beyond documenting the capitalization at issuance, and the same founder shares are frequently covered in both directions. The conditions and the held-through-an-LLC trap are in section “Tax Implications: The Silver Lining of Losses”.

Where stacking stops being planning and becomes a sham. The technique is real, and the version circulating in founder forums is not the technique. A stack works because each trust is a separate taxpayer that genuinely owns the stock, which means a completed gift with real gift tax consequences, an independent trustee exercising actual discretion, and beneficiaries who exist. The abusive variants share a signature: trusts created for unborn children with placeholder beneficiaries, a parent’s trust funded with a token amount that then buys your shares at a convenient valuation, and a trustee chosen because they will do whatever you say. Each of those fails on its own doctrine — a trustee who takes instruction makes the trust your alter ego, a transfer with no economic substance is collapsed under step-transaction principles, and IRC §643(f) lets the IRS treat multiple trusts with substantially the same grantor and beneficiaries as a single trust when a principal purpose was avoiding tax. There is also nothing subtle about the pattern from the outside: a dozen trusts formed in the months before a signed term sheet is a diagram the examiner has seen. Stack early, stack with real gifts, and stack with a trustee who can say no to you — or do not stack.

The Puerto Rico gambit does not work the way it is described. A bona fide resident of Puerto Rico may exclude Puerto Rico-source income from US tax under IRC §933, “Income from sources within Puerto Rico”, and the island’s incentives code can reduce the local rate on qualifying gains to zero. Founders are routinely told this means moving before the sale converts the whole exit into tax-free income. It does not. Sourcing runs through IRC §937, “Residence and source rules involving possessions” and its regulations, under which gain on property you held before establishing residency is Puerto Rico-source only to the extent it accrued after the move. Under Treas. Reg. §1.937-2(f), gain on property you owned before the move is US-source in full if you were a US resident in any of the ten years before the year of sale, unless you elect to split it by holding period — and the split gives Puerto Rico only the appreciation after your arrival. The appreciation built up while you were founding and growing the company — which is essentially all of it — stays US-source and fully taxable. Bona fide residency itself is not a formality either: it requires satisfying presence, tax home, and closer-connection tests, which is precisely why “move down, sell, move back” is the fact pattern the IRS built an enforcement campaign around. Puerto Rico is a genuine long-term structure for someone relocating a life and generating future gains there. It is not a same-year shelter for a gain you have already earned.