QSBS (Qualified Small Business Stock)

Definition

QSBS (Qualified Small Business Stock) is stock in a small US C corporation that lets individual shareholders exclude up to 100% of their capital gain from federal tax when they sell, if they meet the holding period and other tests. The rule comes from Section 1202 of the Internal Revenue Code and is meant to reward long-term investment in small, growing businesses.

How it comes up in fundraising

Founders think about QSBS at two moments: at incorporation, when choosing a C corporation and issuing stock early starts the clock, and at exit, when an acquisition or secondary sale can be partly or fully free of federal capital gains tax.

What is QSBS (Qualified Small Business Stock)?

QSBS is a tax status that attaches to specific shares, not to a company as a whole. When a non-corporate taxpayer, such as a founder, early employee, angel or certain funds passing gains through to individuals, sells shares that qualify, a portion or all of the gain can be excluded from federal tax.

The benefit sits in Section 1202 of the Internal Revenue Code. Congress designed it to encourage people to put money and work into small domestic businesses and to stay invested for years rather than months.

Three ideas make QSBS easier to understand:

• It is share by share. Two people at the same company can have different QSBS outcomes depending on how and when they got their stock.
• It is about the company at the time of issuance. Many of the tests look at the company when the shares were issued, not when they are sold.
• Nobody stamps it as approved. The IRS does not confirm QSBS status in advance unless you obtain a private letter ruling, so your eligibility rests on the records you keep.

How does QSBS (Qualified Small Business Stock) work?

QSBS works through a mix of company tests, shareholder tests and a holding period. If all of them are met, the gain on sale is partly or fully excluded, up to a cap per issuer.

The holding period

The rules changed with the One Big Beautiful Bill Act. Stock acquired after July 4, 2025 has a phased schedule, while older stock follows the original rule.

The clock starts when actual stock is issued to you. Holding a SAFE, a convertible note, a warrant or an option does not start the holding period. The clock begins only when those instruments convert or are exercised into shares.

The cap per issuer

The exclusion is limited for each company you hold shares in. The cap is the greater of:

• $15 million for stock acquired after July 4, 2025 ($10 million for older stock), or
• ten times your basis in the stock.

The $15 million figure and the asset threshold are adjusted for inflation going forward. Because the cap applies per taxpayer and per issuer, it is a ceiling for each person at each company, not a lifetime limit across all of your investments.

Which companies and shares qualify for QSBS (Qualified Small Business Stock)?

The tests fall into two groups: tests about the company and tests about how you got the stock.

Company tests

• C corporation only. Stock issued by S corporations, partnerships or LLCs taxed as partnerships does not qualify.
• Domestic. The company must be a US corporation.
• Asset ceiling. Aggregate gross assets must not exceed $75 million before and immediately after the stock is issued. This threshold was raised from $50 million by the One Big Beautiful Bill Act.
• Active business. At least 80% of the company's assets by value must be used in the active conduct of a qualified trade or business.
• Excluded fields. Service businesses in health, law, engineering, consulting, financial services, and any business whose main asset is the reputation or skill of its employees do not qualify. Banking, insurance, farming, extraction businesses, and hotels or restaurants are also excluded.

Stock tests

• Original issue. You must get the shares directly from the company, in exchange for money, property or services. Shares bought from another shareholder on the secondary market do not qualify for the buyer.
• No disqualifying redemptions. If the company buys back more than 5% of its stock value within a two-year window around your issuance, your shares can be disqualified. This is one of the less obvious traps.

How is the QSBS (Qualified Small Business Stock) exclusion calculated?

The math has two steps. First find the cap, then apply the exclusion percentage.

1. Cap = the greater of $15 million (or $10 million for older stock) and 10 x your basis.
2. Eligible gain = the smaller of your actual gain and the cap.
3. Excluded gain = eligible gain x the exclusion percentage for your holding period (50%, 75% or 100% for newer stock).
4. Taxable gain = actual gain minus excluded gain.

A founder with a very low basis will almost always land on the flat dollar cap. An investor who put in a large cheque may find that 10 x basis is the bigger number, which is why the basis test matters for angels and early funds. If you want to see how your stake changes over rounds before running this math, the cap table calculator helps you model ownership.

QSBS (Qualified Small Business Stock) vs 83(b) election

These two often get mixed up because founders deal with them at the same moment. They are different rules that work together.

• QSBS decides how much of your gain is taxed when you sell.
• An 83(b) election decides when you are taxed on restricted stock that vests over time. Filing it means you recognise any income at grant, usually when the value is very low, instead of as shares vest.

The link between them is timing. Early option exercises paired with an 83(b) election can start the QSBS holding period sooner, because you hold actual stock earlier. A low 409A valuation at the time of early exercise keeps the upfront cost small. Without the 83(b) filing on unvested stock, the start date for holding purposes can become harder to defend.

Why does QSBS (Qualified Small Business Stock) matter to founders?

For a founder, equity is usually the biggest asset they will ever own, and it is mostly gain. A founder who paid almost nothing for shares can have a gain close to the full sale price. That is exactly the situation where an exclusion capped at $15 million or more per person can change what they take home from an acquisition.

It matters in a few other ways too:

• Entity choice. Forming as an LLC or S corporation first and converting later can push back when qualifying stock is issued, or complicate the analysis.
• Timing of liquidity. A secondary sale before the holding period is met may leave the benefit on the table. Under the new schedule, waiting from year three to year five can double the excluded share.
• Team equity. Early employees who exercise options and hold stock can benefit as well, which makes equity a stronger part of the offer.
• Planning room. Because the cap applies per taxpayer, some founders gift shares to non-grantor trusts or family members so that each holder has their own cap. This is called stacking and needs specialist advice.
• Rollover. In some cases, gains from QSBS held more than six months can be rolled into new QSBS-eligible stock to defer tax.

It is worth knowing that QSBS is debated. Critics argue that it mostly benefits wealthy investors and has not increased the capital flowing to small businesses, so the rules could change again.

How do founders use QSBS (Qualified Small Business Stock) when raising?

QSBS comes up in fundraising in quieter ways than valuation or terms, but it does come up.

What investors look for

Many angels and some funds care whether their shares will qualify, because it affects their after-tax return. During due diligence, expect questions such as:

• Has the company always been a C corporation, and if not, when did it convert?
• What were gross assets at each issuance?
• Has the company redeemed any stock, and when?
• Does the business fall into any excluded field?

Points to manage in each round

• Asset size. A large priced round can push gross assets over $75 million. Shares issued after that point will not qualify, even though earlier shares keep their status.
• Buybacks. Repurchasing a departing co-founder's shares or offering a company-led tender near a financing can trigger the redemption rule. Check the two-year window before agreeing.
• Instrument choice. SAFEs and notes do not start the clock. That is not a reason to avoid them, but investors should know their holding period starts at conversion.
• Business description. How you describe what the company does in filings and decks should match reality. A product company that looks like a consultancy on paper invites questions.

Keep the records

Since eligibility depends on documentation, keep board consents, share issuance records, a clean cap table, balance sheets at each issuance date and any QSBS representation letters in one place. A well-organised data room makes this easy to hand to buyers and investors. The Round Funded Data Room is free to build and share on every plan, which suits keeping these records ready for diligence.

Common mistakes with QSBS (Qualified Small Business Stock)

• Assuming the company qualifies forever. Status is tested at issuance and through most of your holding period. Drifting into an excluded field or failing the 80% active asset test can hurt.
• Confusing options with stock. Unexercised options do not count. Many employees learn at exit that their clock never started.
• Ignoring redemptions. A small buyback that looks routine can disqualify shares issued around the same time.
• Starting as the wrong entity. Operating as an LLC for the first years means early value may not be covered.
• Selling too early. A secondary sale at year two of new stock gets no exclusion, and older stock needs more than five years for any benefit.
• Buying on the secondary market and expecting QSBS. The buyer does not get original issue status.
• Skipping advice. State tax treatment, stacking, rollovers and the interaction with other rules are technical. Work with a tax adviser before acting, and treat this page as general information, not tax advice.

Worked example

Frequently asked questions

Round Funded resources

• Startup data room
• SAFE note explained
• Equity
• Glossary

Sources

• law.cornell.edu: 26 U.S. Code 1202 (Cornell LII)
• mgocpa.com: What Is Qualified Small Business Stock (QSBS)?
• morganstanley.com: How Company Founders Can Maximize Tax Savings
• taxlawcenter.org: Qualified small business stock