Qualified Small Business Stock: A Wider Exclusion Reshapes Exit Planning

For owners thinking about an eventual sale, one line in the 2025 tax law deserves a closer read than it usually gets. The One Big Beautiful Bill Act, signed on July 4, 2025, expanded Section 1202 of the tax code, the provision that lets qualifying shareholders exclude a large share of the gain on a business sale from federal capital-gains tax. The exclusion is now larger, reaches companies that were previously too big to use it, and, for the first time, delivers a partial benefit before the traditional five-year hold. What has not changed is the timing lesson underneath it: the payoff belongs to owners who set up the structure long before a deal is on the table.

What the Exclusion Actually Does

Section 1202 lets the owner of "qualified small business stock," usually shortened to QSBS, exclude gain when they sell that stock. QSBS is stock issued by a domestic C-corporation, meaning a company taxed as a separate entity rather than a pass-through, that meets size and business-type tests and that the owner received at original issuance rather than buying from an earlier holder. When the requirements are met, a founder or early investor can sell and pay no federal capital-gains tax on a capped portion of the gain.

The dollars involved are not small. An owner selling appreciated stock generally faces a combined federal rate near 23.8 percent on long-term gains, the 20 percent capital-gains rate plus the 3.8 percent net investment income tax. Excluding several million dollars of gain from that calculation can change the after-tax result of a sale by seven figures. That is why the provision, long treated as a startup-and-venture footnote, is now part of mainstream exit planning for privately held companies.

The Three Changes That Matter

For stock issued after July 4, 2025, the new law made three adjustments, and each widens the door.

First, the exclusion cap rose from $10 million to $15 million per company, with inflation indexing beginning after 2026. In practice, the excluded amount is the greater of that cap or ten times the owner's basis in the stock, so founders with low basis are usually working against the dollar cap.

Second, the ceiling on company size rose from $50 million to $75 million in gross assets, also indexed after 2026. A company can now raise more capital or grow larger and still issue stock that qualifies at the time of issuance, which brings more established businesses into range.

Third, and most consequential for planning, the holding period became tiered. Stock issued after July 4, 2025 earns a 50 percent exclusion at three years, 75 percent at four years, and the full 100 percent at five years. The older rule was all or nothing: no exclusion at all until a full five-year hold. Stock issued on or before July 4, 2025 stays under those prior rules, with a $10 million cap and the full five-year requirement, so the date a company issued its shares now determines which regime applies.

The Entity Question Most Owners Hit First

The requirement that stops many private companies is the C-corporation test. QSBS comes only from C-corporation stock. Most closely held businesses operate as S-corporations or LLCs, pass-through entities whose profits are taxed on the owners' personal returns, and those structures do not produce qualifying stock.

An owner can convert to a C-corporation to begin qualifying, but two facts follow the conversion. The holding-period clock starts at conversion, not at the company's founding, so the countdown to a partial or full exclusion begins fresh on the conversion date. And only appreciation after conversion is eligible; the value built up under the old structure does not qualify. Conversion also carries a C-corporation's own tradeoffs, including a layer of entity-level tax on profits that pass-through owners avoid, so the decision weighs a future capital-gains exclusion against years of potentially higher ordinary tax in the meantime. The balance is specific to each company's profit profile and expected timeline, which is why this is a planning conversation rather than a default move.

The Levers That Shape the Outcome

For owners who already hold, or who convert to, qualifying stock, a few levers determine how much of the benefit they actually capture.

The holding period is the first. Because the exclusion now steps up at three, four, and five years, the timing of a closing can be worth real money. An owner close to a threshold may negotiate a delayed close to cross it, or price the extra tax into the deal if delay is not possible.

Section 1045 offers a second lever when a sale arrives too soon. If an owner sells QSBS before meeting the holding period, reinvesting the proceeds into new qualifying stock within 60 days can defer the gain and carry the original holding period forward, allowing the five-year test to be met through a chain of qualifying investments.

A third lever is the per-owner nature of the cap. The exclusion applies per taxpayer and per company, so shares held by different taxpayers each carry their own cap. Owners sometimes gift stock to family members or to non-grantor trusts, each of which can claim a separate exclusion, multiplying the total gain that escapes tax. Timing governs whether this works. Gifts arranged after a sale is effectively agreed can be unwound by the Internal Revenue Service under the assignment-of-income doctrine, which treats income as belonging to the person who earned the right to it. Planning of this kind needs to happen well before a letter of intent, not during diligence.

Why This Is Worth Attention Now

The expansion lands as deal activity is recovering. Middle-market transactions are finding their footing again after a slow stretch, and more owners are lining up exits over the next few years. A wider exclusion raises the reward for structuring decisions made early, which means the choices an owner makes in 2026, about entity type, about when to issue or convert stock, about how ownership is held across a family, can shape the tax bill on a sale that is still years away.

Two cautions belong alongside the opportunity. The enhanced rules apply only to stock issued after July 4, 2025, so many existing shares remain under the older, narrower regime. And practitioner commentary has run ahead of formal guidance from the Internal Revenue Service on several mechanics, including conversions from LLCs, stacking across trusts, and gifting. The framework is clear; some of the edge cases are not yet settled. That gap is a reason to plan deliberately and document carefully, with advisors who follow the guidance as it develops.