QSBS Explained: How Section 1202 Can Let Startup Investors Skip Capital Gains Tax

For most investors, selling stock at a profit triggers a federal capital gains tax bill. But a provision tucked into Section 1202 of the Internal Revenue Code offers a striking exception: certain early investors in qualifying small companies can exclude some or even all of their gain from federal income tax. This benefit, known as the Qualified Small Business Stock (QSBS) exclusion, has become a significant planning tool for startup founders, employees who exercise stock options, and venture and angel investors.

What Counts as Qualified Small Business Stock

To qualify as QSBS under Section 1202, stock generally must meet several conditions at the time it is issued and while it is held, according to the IRS. The issuing company must be a domestic C-corporation, not an S-corporation, partnership, or LLC. The corporation's aggregate gross assets must not exceed $50 million at any time before and immediately after the stock is issued (the OBBBA raised this threshold to $75 million for stock issued after July 4, 2025, with future inflation adjustments). The stock must be acquired directly from the corporation, typically in exchange for money, property, or services, rather than purchased from another shareholder on a secondary market.

The company also must be engaged in an active trade or business, which excludes certain service-oriented fields such as health, law, accounting, financial services, farming, hospitality, and businesses whose principal asset is the reputation or skill of employees. This carve-out is one reason many professional services firms cannot offer QSBS-eligible stock to investors.

How Much Gain Can Be Excluded

The size of the exclusion depends on when the stock was acquired. Stock acquired after August 10, 1993 and before February 18, 2009 qualifies for a 50% exclusion. Stock acquired between February 18, 2009 and September 27, 2010 qualifies for a 75% exclusion. Stock acquired after September 27, 2010 qualifies for a full 100% exclusion, which also means the excluded gain is not treated as an alternative minimum tax preference item for that later category, according to IRS guidance and the statute itself.

There is a dollar cap on how much gain can be excluded per issuer. Under longstanding law, the exclusion is limited to the greater of $10 million or 10 times the taxpayer's adjusted basis in the stock. The One Big Beautiful Bill Act, signed into law in 2025, increased this cap to $15 million for stock acquired after July 4, 2025, with future inflation indexing, and it also introduced a tiered holding period allowing partial exclusions after three or four years rather than requiring a full five-year hold for that newer stock. Investors should confirm current thresholds directly with IRS publications or a tax professional, since effective dates and phase-ins can be technical.

The Five-Year Holding Period

For stock governed by the pre-2025 rules, the stock must be held for more than five years to claim any exclusion. There is no partial credit for shorter holding periods under those older rules. Investors who sell early, even by a matter of days, forfeit the exclusion entirely on that stock, though Section 1045 offers a possible workaround by allowing gain to be rolled into replacement QSBS within 60 days without immediate taxation.

Practical Considerations for Investors

• Ask the company for written confirmation of QSBS eligibility, including gross asset figures at issuance and the corporate structure, since this information is not always visible to outside investors.
• Keep detailed records of the stock issuance date, purchase price, and any changes in ownership, because gifted or inherited QSBS can carry over eligibility under specific rules.
• Understand that state tax treatment of QSBS varies; some states, including California, do not conform to the federal exclusion.
• Consult a qualified tax advisor before a sale to confirm which version of the rules applies, especially for stock that straddles the pre- and post-2025 statutory changes.
• Be aware that converting a company from an LLC to a C-corporation, or vice versa, can affect QSBS eligibility going forward.

Why It Matters

The QSBS exclusion can materially change the after-tax return on early-stage investing, which is part of why it draws attention from founders negotiating equity, employees weighing option exercises, and venture investors structuring funds. Because the benefit is written into the tax code rather than granted through a discretionary program, it has remained a durable, if underused, planning tool since its introduction in 1993. Recent legislative changes broadening the asset threshold and cap suggest continued policy interest in encouraging investment in small domestic businesses, making it worth understanding for anyone participating in early-stage company financing.