Qualified Small Business Stock (QSBS): The Tax Benefit Most Founders Don’t Plan for Until It’s Too Late

The term “qualified small business stock” has a name that could, understandably, put you to sleep.

But bear with me for a moment. 

Let’s say your founder shares, which likely cost you next to nothing, sell for $10 million. The federal tax bill on that gain probably comes to $2.4 million. If those shares meet the criteria for qualified small business stock, it could be zero.

If I had to guess, you’re suddenly wide awake. The operative word here is “qualified,” which relies on your answers to several questions: 

• When was your stock issued? 
• What kind of entity issued it? 
• How much did the company hold in assets at that point?

Below, I’ll walk through how the exclusion works, who qualifies, how to start the clock, and what can disqualify shares.

What Is Qualified Small Business Stock?

Section 1202 of the Internal Revenue Code (IRC) lets eligible holders of qualifying stock exclude some or all of their gain from federal income tax when they sell. The exclusion is capped per taxpayer, per issuing company, at the greater of a fixed dollar amount or 10 times your adjusted basis in the stock. Founder shares typically have a negligible cost basis, so the dollar amount is usually the cap that applies.

The rules that govern your stock depend on when it was issued:

With newer stock (i.e., issued after July 4, 2025), a portion of your gain may not be eligible for the exclusion (e.g., 25% if you’ve held for at least four years but less than five). That ineligible portion is taxed at 28%, plus the 3.8% net investment income tax (NIIT; 31.8% combined), but only up to the $15 million exclusion cap. Any gain above the cap is taxed at the regular long-term rate.

To visualize the impact, here’s how a $10 million gain is taxed at each tier:

Hypothetical, for stock issued after July 4, 2025, federal tax only. The taxable portion at the partial tiers is taxed at 28% plus the 3.8% net investment income tax. Where no exclusion applies, the rate is 23.8% (the 20% long-term capital gains rate plus the 3.8% net investment income tax), assuming a top-bracket taxpayer and stock held more than a year. 

A couple of mechanics to know before you build a plan around any of these numbers:

• The $15 million is reduced by prior exclusions. Any QSBS gain you’ve already excluded from the same issuer counts against it, including gain on stock issued before July 5, 2025. That said, it’s particularly complicated when partial 50% or 75% exclusions are involved, so don’t assume the remaining cap simply equals $15 million minus the amount previously excluded.
• Excluded gain isn’t subject to the net investment income tax. A fully excluded gain at the 100% tier isn’t treated as an alternative minimum tax (AMT) preference item either. Talk with your accountant about how the partial tiers are treated.

QSBS Stacking

As I mentioned, the cap applies per taxpayer. If you were to gift shares to a family member or to separate non-grantor trusts, you could give each recipient their own exclusion; the recipient assumes the donor’s holding period. 

Let’s say a founder sells their business and recognizes a $40 million gain. Shares were acquired in 2015 and have been held more than five years, so the full $10 million exclusion applies. In turn, the founder’s taxable gain is $30 million, which translates to $7.14 million in federal taxes (23.8% x $30 million). 

However, we’ll now assume the founder gifted 25% of the business to each of three non-grantor trusts (keeping the remaining 25%) well before the sale while the company was worth a fraction of its eventual value. In that case, the entire gain could qualify for full exclusion from federal taxes. 

Of course, this is a simplified example, and there are important caveats: 

• The gifts have to be complete and bona fide, and made well before a sale is in motion.
• The recipient has to be a separate taxpayer. A grantor trust generally doesn’t qualify, and married couples filing separately split a single cap.
• Gifts use your lifetime exemption (currently $15 million per person) with a 40% rate above it.
• Gifting an interest in a partnership that holds QSBS falls outside the gift exception.

Stacking has major tax and estate planning implications, so your attorney and accountant should be involved from the start.

Does Your Stock Qualify as QSBS?

There are several core tests to run. Missing any of them could eliminate the benefit.

Note: Certain stock redemptions around the issuance date can also jeopardize QSBS status, even if the requirements above are otherwise satisfied.

The Gross Assets Test

The company’s gross assets must stay under the limit at every point before the stock is issued, and again at the moment right after issuance, once the money raised in that round is counted. Assets count at cash plus the adjusted basis of other property, which can be far below market value for a company whose main asset is software or IP. Property contributed to the company counts at fair market value.

Growth after issuance doesn’t taint stock that’s already been issued. Stock issued after the company crosses the line won’t qualify. That’s why the date of issuance is so important.

Qualified Trade or Business

The statute excludes several fields:

• Services in health, law, engineering, architecture, accounting, actuarial science, performing arts, consulting, athletics, financial services, and brokerage
• Any business whose principal asset is the reputation or skill of its employees 
• Banking, insurance, financing, leasing, and investing
• Farming
• Oil, gas, and mineral extraction
• Hotels, motels, and restaurants

Treasury hasn’t issued regulations on these categories, so guidance comes mostly from private letter rulings, which technically bind only the taxpayer who requested them. The pattern in those rulings is that the IRS looks at what the company sells. A law firm or consultancy sells the judgment of its people, which is what the catch-all is aimed at. A software or product company sells a product, even when it employs specialists, and the IRS has generally declined to treat those employees’ skill as the company’s principal asset. 

If your company straddles that line, I recommend getting a professional opinion before banking on the exclusion.

The Active Business Requirement

At least 80% of the company’s assets, by value, must be used in the active conduct of a qualified business for substantially all of your holding period. The statute doesn’t define “substantially all.”

Cash held for reasonably required working capital counts as “active,” as does cash held for investment that’s expected to fund R&D or working capital needs within two years. Once the corporation is two years old, no more than half of its total assets can count as active solely because they’re working capital or earmarked for R&D. 

Separate limits (generally 10%) apply to stock in other corporations and to real estate that isn’t used in the business, and any period with an S election in effect counts against the company. A large funding round that sits in a bank account for years can push the company below the 80% line, and the statute offers no cushion.

Section 1045 Rollover

If you have to sell before the holding period runs out, Section 1045 offers a way to defer the gain, subject to the following conditions:

• You held the original stock for more than six months.
• You reinvest the proceeds in replacement QSBS within 60 days of the sale.
• You make the election on a timely filed return.
• The replacement issuer meets the active business requirement for at least six months after issuance.

Your holding period tacks onto the replacement stock, so the clock keeps running toward the exclusion. The 60 days run from the sale date with no extension, and the replacement has to be QSBS issued by another company, so line it up before you close.

What Starts the Clock on QSBS?

The holding period starts at different points in time depending on how you received your equity:

• Stock purchase: Date of purchase
• Restricted stock with a timely 83(b) election: Grant date
• Restricted stock without an 83(b) election: Each vesting date
• Stock options (ISOs and NSOs): Exercise date
• RSUs: Settlement/share issuance date (which may or may not be the vesting date)

I’ll walk through an example. Two founders receive identical restricted stock grants that vest over four years. The first files an 83(b) election within 30 days, and her five-year clock starts on the grant date. The second doesn’t, so each vesting tranche starts its own clock. His last tranche vests in year four, which means that tranche doesn’t clear its five-year holding period until year nine. That said, an 83(b) election means recognizing any taxable spread at grant instead of as the shares vest, even if the stock is later forfeited.

For options, an unexercised option isn’t stock, so the clock doesn’t run. Exercising early, while the company is still under the gross assets threshold, can decide whether the stock qualifies at all. Once the company is past the gross asset limit, stock issued on exercise won’t count. Exercising ISOs can also trigger alternative minimum tax on the spread, which is a separate issue from the QSBS exclusion.

Entity Structure: C-Corp Conversions and Pass-Throughs

LLCs and S corporations don’t issue QSBS. If your company started as one of them, converting to a C corporation can create QSBS going forward, with a few conditions:

• The clock starts at conversion, not when the business was formed.
• Only appreciation after the conversion is eligible. Any accumulated gain built up beforehand stays taxable. For purposes of the 10x cap, the stock’s basis starts at fair market value at conversion.
• Keep in mind, ending an S election doesn’t by itself satisfy original issuance, so the conversion has to be structured deliberately.

The tradeoff is corporate-level tax. Conversion tends to benefit high-growth companies that reinvest everything. It’s not as straightforward for profitable businesses that distribute cash to their owners.

Partnerships follow their own rule. A partner can claim the exclusion on QSBS the partnership holds, but only if they held their interest when the partnership acquired the stock and kept it until the sale. Each partner has their own cap.

How States Treat QSBS

QSBS is a federal benefit, and states decide for themselves whether to follow it. California, Pennsylvania, Mississippi, and Alabama don’t recognize the exclusion, and Hawaii allows only part of it. The list is also changing. New Jersey begins allowing the exclusion for tax years starting in 2026, while Illinois and Oregon require a full addback of the federal exclusion beginning in 2026. 

Take a California founder whose $10 million gain qualifies for the full federal exclusion. The federal tax bill is $0, yet California still taxes the entire gain at up to 13.3%, which comes to about $1.3 million.

What the Sale (and Savings) Are For

A seven-figure tax savings is absolutely a worthwhile pursuit. It also raises a question that no tax rule answers: what is the sale for?

At Five Oceans, these conversations happen simultaneously. Through our Life Strategy framework, we start with your vision for the future, and the planning follows based on your answer. If you’re approaching a sale, our Sudden Liquidity Pain Point Engagement offers structured, one-on-one work with our Life Strategist Ali Campbell, which is designed to slow the moment down and translate that clarity into an intentional financial strategy.

Section 1202 is complex and highly technical, and an accountant and attorney need to confirm the details for your situation. If you’re not sure whether your stock qualifies, I’d be glad to look at the structure.

Talk with me.