QSBS Section 1202: How the Small Business Stock Gain Exclusion Works

Section 1202 is the federal tax provision that rewards long-term ownership of qualified small business stock. The IRS describes the basic mechanic this way: section 1202 lets a shareholder exclude part of the eligible gain on the sale or exchange of QSB stock.^[1] The exclusion is gated on holding period; only QSB stock held more than 5 years is eligible.^[2]

For founders, early employees, and angel investors in a US C corporation, this is one of the highest-impact provisions in the tax code at exit. The smartest planning happens at the original issuance, well before any sale is on the horizon.

Public Law 119-21 was signed on July 4, 2025 and amended section 1202.^[8] The biggest practical change is the corporate-level gross-asset ceiling. The IRS now defines a qualified small business as a domestic C corporation whose gross assets stay at $75 million or below at all relevant measurement points, with the prior $50 million threshold still controlling for stock issued on or before July 4, 2025.^[5]

In other words, the cap stepped up 50% under OBBB. Companies that would have priced their next financing right against the old $50 million ceiling now have more headroom to issue stock that still qualifies as QSBS to the holders. Gross assets are aggregated with any predecessor of the corporation, and a parent-subsidiary controlled group is treated as a single entity for this purpose.^[5]

The exclusion percentage depends on when you acquired the stock. The IRS splits the rules into three acquisition windows.

The IRS lays out the technical eligibility in its investment-income publication. The negative list excludes several specific company types from eligible-corporation status for QSBS purposes: DISCs (or former DISCs), corporations with a section 936 election, regulated investment companies, REITs, REMICs, certain FASITs, and cooperatives.^[7]

The positive side of the rule lives in the active business test. A corporation meets it for any period when the company is an eligible corporation and uses at least 80% of its assets, measured by value, in the active conduct of one or more qualified trades or businesses.^[10] For technology and SaaS startup tax help, the 80% test is usually the easy one. The harder questions are issuance timing and gross-asset measurement.

The acquisition date matters because it dictates which exclusion percentage applies. The IRS guidance is explicit: in deciding which exclusion percentage applies to a QSB-stock gain, the acquisition date is the first day the taxpayer held the stock, after applying the holding-period tacking rules in section 1223.^[11]

For a founder who received shares at incorporation, that is usually a clean date. For an early employee whose stock vested over time, or an investor who received shares in exchange for services, the acquisition date may need to be reconciled with the section 1223 tacking rules before any exit projection is meaningful. Working that out is part of the exit-side modeling that should happen before any letter of intent is signed.

Section 1202 is the back end of the OBBB tax planning story: long-term gain exclusion for founders and investors. The front end is the operating-side reset for the C corporation itself, with full first-year depreciation back under the new rule and a higher expense ceiling. We cover that side in our Did the One Big Beautiful Bill restore immediate R&D expensing? explainer. Modeling both pieces together, the corporation can run leaner cash taxes during the build, and the founders can run cleaner gain math at exit.