Section 1202 QSBS: Tax-Free Gains on Small Business Stock

What is QSBS and Why Does It Matter?

Qualified Small Business Stock, or QSBS, is a special tax provision that allows you to exclude a substantial portion — potentially all — of your capital gains when you sell stock in a qualifying small business. If you purchase shares in a startup or small company while its valuation is below certain thresholds, and you hold the stock for a minimum holding period, you may be able to sell those shares years later with little to no federal capital gains tax.

This is a genuinely powerful benefit. A founder or early employee who buys in at a low valuation and sells after the company appreciates could exclude hundreds of thousands or millions of dollars in gains from taxation.

The benefit became even more valuable recently. The One Big Beautiful Bill Act of 2025 made several significant changes to QSBS rules, depending on when the stock was acquired.

Two Sets of Rules: Old vs. New

QSBS treatment depends on when you purchased the stock:

Old Rules (Stock Purchased Before July 4, 2025)

For stock acquired between August 10, 1993 and July 4, 2025, the original Section 1202 rules apply:

• Company valuation threshold: $50 million in gross assets at the time of stock purchase
• Holding period: Stock must be held for at least 5 years to qualify for any exclusion
• Exclusion: 100% of gains excluded (for stock acquired after September 27, 2010)
• Lifetime exclusion cap: $10 million per taxpayer

New Rules (Stock Purchased After July 4, 2025)

The OBBB Act expanded QSBS for stock acquired after July 4, 2025:

• Company valuation threshold: $75 million in gross assets at the time of stock purchase (increased from $50 million)
• Holding period: Tiered structure now allows partial benefit before 5 years:
  • Hold for at least 3 years: exclude 50% of gains
  • Hold for at least 4 years: exclude 75% of gains
  • Hold for at least 5 years: exclude 100% of gains
• Lifetime exclusion cap: $15 million per taxpayer (increased from $10 million)

The combination of a higher company valuation threshold and earlier partial exclusions makes QSBS more accessible for both founders and early employees at later-stage companies.

Who Can Use QSBS?

QSBS most often applies to founders and early employees at startups and small businesses. To qualify, you must purchase the stock when the company’s total capitalization is below the applicable threshold ($50M or $75M depending on the rule set). At the moment of founding or joining an early-stage startup, the company is almost certainly below this threshold, so your founder shares or early-employee stock purchases will qualify.

As the company grows and its valuation approaches or exceeds the threshold, new stock issuances may no longer qualify as QSBS. But the stock you purchased when the company was small remains QSBS-eligible as long as you hold it for the required period.

The Mechanics: Valuation, Timing, and Holding Periods

To claim QSBS treatment when you sell, three conditions must be met:

1. You purchased the stock when the company’s valuation was below the applicable threshold. The company’s valuation at the time of your purchase determines eligibility — not the valuation when you sell.

2. You held the stock for the required holding period. Under the new rules, you can exclude 50% after 3 years, 75% after 4 years, or 100% after 5 years. Under the old rules, you must hold for 5 years for any exclusion.

3. The stock meets other QSBS criteria. The company must be a C corporation, engaged in an active business (not passive investment), and meet other technical requirements.

Example (simplified): You purchase $100,000 of stock in a startup when the company has $20 million in total assets. Five years later, you sell that stock for $1 million, realizing a $900,000 capital gain. Because you held the stock for five years and you bought the shares when the company valuation was below the threshold, you can exclude 100% of the $900,000 gain from federal taxation. You owe zero federal capital gains tax on that profit.

Compare this to a non-QSBS investment: at the top 20% federal long-term capital gains rate, that same $900,000 gain would cost $180,000 in federal tax — plus an additional 3.8% NIIT if your modified adjusted gross income exceeds the threshold, plus any state capital gains tax. The QSBS exclusion avoids all of that federal tax.

Documentation: Securing Proof of Valuation

The most critical step is obtaining documentation at the time of stock purchase that confirms the company’s valuation. Years later, when you sell and claim QSBS treatment, you’ll need to demonstrate that the company was below the applicable threshold on the purchase date.

Documentation typically takes the form of a 409A valuation — a third-party appraisal that establishes fair market value for tax purposes. Securing this documentation upfront eliminates ambiguity later.

The 83(b) Election Interplay

If you’re an early employee exercising stock options (rather than purchasing shares directly), an 83(b) election may allow you to lock in the fair market value of those shares at the time of exercise. Combined with QSBS, this can be powerful: you exercise options when the company is early-stage (low FMV), make an 83(b) election to start your holding period immediately, and later sell the shares with QSBS treatment.

The key interplay: 83(b) lets you start the QSBS five-year holding period early, maximizing your opportunity to hold long enough for the tax benefit.

The Takeaway

Section 1202 QSBS is a powerful tax benefit for founders and early employees of startups and small businesses. Under the new OBBB Act rules, stock purchased after July 4, 2025 in a company valued below $75 million can yield 50%, 75%, or 100% gain exclusion depending on holding period (3, 4, or 5 years respectively), up to a $15 million lifetime cap. Older rules ($50M company threshold, 5-year holding period, $10M cap) still apply to stock purchased before that date. The key requirement is documentation: secure proof of the company’s valuation at the time you purchased the stock, typically through a 409A valuation. For those with meaningful equity in early-stage businesses, understanding QSBS and planning around its requirements can yield substantial tax savings. If you’re uncertain whether your stock qualifies or how to maximize the benefit, consulting a tax professional is recommended.