The Tax Break That Could Save You Millions at Exit.

Most founders have never heard of QSBS. The ones who have are structuring around it from day one.

Key Takeaways

• Qualified Small Business Stock (QSBS) under IRC Section 1202 may allow founders and early investors to exclude up to 100% of capital gains from federal income tax at exit.

• The exclusion applies up to the greater of $15 million or 10 times your basis in the stock (for stock issued after July 4, 2025). For founders who purchased shares at incorporation, that basis is often near zero, making the 10x multiplier less useful, but the $15 million floor still significant.

• Only C-Corp stock qualifies. Not LLC membership interests, not S-Corp stock, not convertible notes or SAFEs (until they convert into qualifying stock).

• The OBBBA (signed July 4, 2025) introduced tiered exclusions: 50% at three years, 75% at four years, and 100% at five years. You no longer need to wait the full five years to benefit.

• Several states, notably California, do not recognize the QSBS exclusion. Your state tax bill may still be substantial.

The Exclusion Nobody Talks About Early Enough

You incorporate your Delaware C-Corp. You purchase founder shares at $0.0001 per share. You file your 83(b) election. You start building.

Five years later, you sell the company for $40 million. Your shares are worth $8 million. Under normal circumstances, you would owe federal capital gains tax on nearly all of it, somewhere around $1.6 million at the current 20% long-term rate, plus the 3.8% net investment income tax.

With QSBS, you may owe zero federal capital gains tax on that $8 million. The entire gain could be excluded. And since the One Big Beautiful Bill Act (OBBBA) was signed into law on July 4, 2025, the benefits are even more accessible than before.

This is not a loophole. It is a deliberate incentive written into the tax code to encourage investment in small businesses. And most founders either do not know about it or learn about it too late to benefit.

How Section 1202 Works

IRC Section 1202 provides a federal income tax exclusion for gains from the sale of Qualified Small Business Stock. The exclusion percentage depends on when the stock was acquired:

• Stock acquired after September 27, 2010: 100% exclusion

• Stock acquired between February 18, 2009 and September 27, 2010: 75% exclusion

• Stock acquired before February 18, 2009: 50% exclusion

For any startup incorporated today, the 100% exclusion applies. Unlike many tax benefits, there is no special election required. If the stock qualifies and the holding period is met, the exclusion applies automatically.

The Five Requirements

To qualify, all five of these must be true:

1. The stock must be in a domestic C-Corporation.

2. The stock must be acquired at original issuance, meaning you bought it directly from the company, not from another shareholder on a secondary market.

3. The corporation’s aggregate gross assets must not exceed $75 million at the time the stock is issued (for stock issued after July 4, 2025, indexed for inflation starting in 2027; $50 million for earlier stock).

4. The corporation must be an active business, at least 80% of its assets must be used in the active conduct of a qualified trade or business.

5. You must hold the stock for at least three years to receive any exclusion.

What Counts as a Qualified Trade or Business

Most technology companies, SaaS businesses, and product companies qualify. Certain industries are excluded:

• Professional services (health, law, engineering, accounting, consulting, financial services)

• Banking, insurance, and financing

• Farming

• Mining and natural resources

• Hospitality (hotels, restaurants, similar businesses)

If your startup is a software company, a marketplace, a hardware company, or a biotech company, you are likely in qualifying territory.

Note: The “professional services” exclusion is broader than most people expect. If your company’s primary revenue comes from services performed by employees in fields like engineering, architecture, or consulting, it may not qualify, even if you also have a software product. The IRS looks at where the majority of value is created.

The $15 Million Floor and the 10x Multiplier

For stock issued after July 4, 2025, the exclusion is capped at the greater of $15 million of gain (up from $10 million under prior law), or 10 times the adjusted basis of the stock.

For founders who purchased shares at incorporation for fractions of a penny, the adjusted basis is tiny. Ten times a $500 basis is $5,000, not helpful. But the $15 million floor means you can still exclude up to $15 million in gain per issuer.

For investors who purchase stock at a higher price, the 10x multiplier becomes more meaningful. The per-issuer limit applies per taxpayer. Married couples filing jointly can potentially exclude up to $30 million.

The 10x basis rule is more powerful than it first looks. If you contributed property worth $2 million to the corporation in exchange for stock, your 10x cap is $20 million, even if your tax basis is close to zero.

The Holding Period, Now Tiered

Under prior law, you needed to hold QSBS for at least five years. The OBBBA introduced a tiered structure for stock issued after July 4, 2025:

The holding period clock starts on the date you acquire the stock. For founders who purchase restricted stock at incorporation and file an 83(b) election, the clock starts on the date of purchase, one of the reasons the 83(b) election is so important.

For employees who exercise stock options, the clock starts on the date of exercise, not the date of grant. Note that the non-excluded portion of gain at the three- and four-year tiers is taxed at 28%, not the standard 20% rate. Run the numbers before deciding whether an early sale makes sense.

What Starts the Clock

The holding period begins at different points depending on how the stock was acquired:

• Stock purchases: The day after acquisition

• Stock options: The exercise date, not the grant date

• Restricted stock with 83(b) election: The date of the 83(b) election

• Gifts and inheritance: The recipient tacks on the transferor's holding period

This is why the 83(b) election matters so much for QSBS purposes. Filing the 83(b) within 30 days of receiving restricted stock starts the QSBS clock immediately. Without it, the clock does not start until each tranche vests, which can push the five-year requirement years further out.

The State Tax Problem

If you are a California resident, you will owe California capital gains tax on the full gain regardless of QSBS. At California’s top rate of 13.3%, this can be significant. Some founders relocate to no-income-tax states before a sale specifically for this reason, though California aggressively audits these moves.

Common Mistakes

• Choosing an LLC instead of a C-Corp. LLC membership interests do not qualify as stock under Section 1202. If you incorporate as an LLC and later convert, the holding period begins at conversion and all the time spent as an LLC is lost.

• Not filing the 83(b) election. Without it, the holding period may not start until each tranche of stock vests. The 30-day window is absolute: no extensions, no exceptions.

• Ignoring the gross assets test. Once the corporation's gross assets exceed $75 million, any stock issued after that point does not qualify. If you raise a large round, confirm whether stock issued afterwards still qualifies.

• Secondary transfers between founders. If one founder transfers stock to another, the receiving founder does not get QSBS treatment on those shares. QSBS requires original issuance, and a founder-to-founder transfer is a secondary sale even at a nominal price.

• Redemptions that trigger anti-churning rules. If the corporation redeems stock in the period around a QSBS issuance, the anti-churning rules under Section 1202(c)(3) can disqualify the stock. Exceptions exist for termination, death, disability and divorce, but the rules are strict.

• Assuming QSBS applies to converted SAFEs without checking. The clock starts at conversion, not when the SAFE was signed.

• Not keeping records. You need to document your stock purchase date, purchase price, the company’s gross assets at the time, and the company’s business activities.

Strategies for Maximizing the Exclusion

Sell low-basis and high-basis stock together. The 10x basis cap is calculated annually. Selling both in the same year can materially increase the total exclusion.

Contribute appreciated property. For QSBS purposes, stock basis equals the fair market value of contributed property, not the tax basis. This inflates the 10x cap.

Gift QSBS to family members. Each recipient gets their own Section 1202 limitation. A shareholder with $40 million in potential gains could distribute stock across family members to shelter more of it.

Incorporate before exceeding the asset cap. If a partnership is approaching the $75 million threshold, incorporating before crossing it preserves QSBS eligibility.

Corporate Transactions and QSBS

QSBS status can survive mergers and reorganizations under Section 368. In a qualifying reorganization, stock received in exchange for QSBS maintains its status even if the new corporation does not independently qualify.

The Section 1045 rollover allows taxpayers to defer gain on QSBS held for more than six months by reinvesting in new QSBS within 60 days. Unlike the Section 1202 exclusion, this requires an affirmative election on the tax return.

What You Should Do Now

• If you are incorporating, form a C-Corp and purchase your founder shares at the lowest defensible price.

• File your 83(b) election within 30 days of purchasing restricted stock.

• Keep a record of the company’s gross assets at the time of your stock purchase.

• Note the date you acquired your stock. Mark your calendar for five years out.

• If you are approaching an exit before the five-year mark, talk to your tax advisor about whether delaying is worth it.

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