QSBS / Section 1202: How Founders Can Exclude Up to $15M in Capital Gains

If you founded or joined a startup in the last decade, the single largest tax planning lever available to you may be one you have never heard called by its name: Qualified Small Business Stock, or QSBS. Section 1202 of the Internal Revenue Code lets eligible shareholders exclude up to $15 million (or 10 times their basis, whichever is greater) of federal capital gains tax-free at exit. For a founder selling stock acquired at a fraction of a cent, that exclusion can be the difference between paying nothing and writing a 23.8% federal check on tens of millions of dollars.

The catch: QSBS rules are technical, the holding-period clock starts at issuance (not exercise or vest), and California does not conform to Section 1202 at all. Bay Area founders who plan well can shelter the federal portion entirely. Bay Area founders who do not plan can still owe California up to 13.3% on the full gain, even when their federal liability is zero.

This guide covers what QSBS is, the eligibility tests, the changes from the One Big Beautiful Bill Act of 2025 (OBBBA), stacking strategies for amounts above the cap, and the California gotcha that catches most first-time founders. We work through these scenarios constantly with our equity compensation team at Silicon Valley Tax.

What is QSBS?

Qualified Small Business Stock is shares of a domestic C corporation that meet the requirements of IRC Section 1202. When you sell QSBS that you have held for the required period, you can exclude a percentage of the capital gain from federal income tax, up to a per-issuer cap. For shares acquired after September 27, 2010, that exclusion is 100% federal, with no Alternative Minimum Tax add-back and no 3.8% Net Investment Income Tax.

To qualify, the stock must meet five core tests:

1. C corporation issuer. The company must be a domestic C-corp at the time of issuance and substantially throughout your holding period. LLCs and S-corps do not qualify; conversions can preserve QSBS status if structured correctly.
2. Gross assets test at issuance. The company's aggregate gross assets must be at or below $75 million (raised from $50 million for stock issued after July 4, 2025) immediately before and after your shares are issued.
3. Originally issued. You must have acquired the stock directly from the company in exchange for cash, property (other than stock), or services. Secondary purchases on the open market or from another shareholder do not qualify.
4. Qualified trade or business. The company must use at least 80% of its assets in an active trade or business that is not on the disqualified list (which includes most personal-service businesses like law, accounting, consulting, health, financial services, brokerage, and any business whose principal asset is the reputation or skill of one or more employees). SaaS, hardware, biotech, fintech infrastructure, marketplaces, and most tech operating businesses generally qualify.
5. Holding period. Under the post-OBBBA rules for stock issued after July 4, 2025, you receive a tiered exclusion based on how long you have held the shares. Stock issued before then still requires a strict five-year hold for any benefit.

The Tax Benefit, by the Numbers

For shares acquired after the 2010 Small Business Jobs Act, the federal exclusion at full eligibility is 100%. The per-issuer cap is the greater of:

• $15 million (for QSBS issued after July 4, 2025, indexed to inflation going forward), or
• 10 times your aggregate adjusted basis in the QSBS sold during the taxable year.

For QSBS issued before July 5, 2025, the cap remains the greater of $10 million or 10x basis, and the cap is not inflation-indexed.

Federal exclusion percentage by holding period (post-OBBBA)

Holding Period	Stock Issued After 7/4/2025	Stock Issued 9/28/2010 to 7/4/2025
Less than 3 years	0% (no exclusion)	0% (no exclusion)
3 years	50% excluded	0%
4 years	75% excluded	0%
5+ years	100% excluded	100% excluded

OBBBA's tiered structure is a meaningful change: founders who exit between three and five years now get partial relief that did not exist before. Pre-OBBBA QSBS still follows the old cliff rule — five years or zero.

Example. You founded a C-corp in 2026, received 10 million shares of common stock at $0.0001 per share (basis: $1,000), and sell those shares five years later for $20 million. Your gain is roughly $20 million. Because 10x your basis is only $10,000, the applicable cap is $15 million. You exclude $15 million from federal tax; the remaining $5 million is taxed at long-term capital gains rates (20% federal plus 3.8% NIIT for high earners). Federal tax saved: roughly $3.57 million.

The California Gotcha

California is one of a small group of states (along with Pennsylvania, New Jersey, and a few others) that does not conform to Section 1202. California Revenue and Taxation Code section 18152.5, which previously offered a partial 50% state exclusion for in-state QSBS, was effectively repealed in 2013 after the Cutler v. Franchise Tax Board ruling found the in-state-only requirement unconstitutional. Since then, California has provided no QSBS exclusion of any kind.

For a San Jose founder, this means the gain that is fully tax-free federally is still taxed by California at its standard capital gains rates — up to 13.3% for the top bracket (or 14.4% if the mental-health surcharge applies to your gain). On a $15 million federal exclusion, that is up to $2.16 million owed to the Franchise Tax Board even when you owe zero to the IRS.

This is the single most expensive surprise we see at exit. The defensible planning moves include establishing residency in a no-tax state in advance of a known liquidity event, gifting shares to non-grantor trusts in QSBS-friendly states, or simply pricing the California tax into the exit plan. None of these work if you find out about the issue after the wire hits.

Stacking: Multiplying the Exclusion Above $15M

The $15 million cap is per taxpayer per issuer. A founder with a much larger expected gain can multiply the exclusion through a strategy known as stacking — gifting QSBS to additional taxpayers, each of whom gets their own $15 million cap.

The two most common stacking structures:

• Spouse and adult children. An outright gift of QSBS to a spouse or adult child transfers basis and holding period. Each recipient becomes their own taxpayer with their own $15 million cap. Annual gift tax exclusion and lifetime exemption planning matters here.
• Non-grantor trusts. A properly structured non-grantor trust is a separate taxpayer for income tax purposes. Founders frequently set up several Delaware or Nevada non-grantor trusts for the benefit of children, fund each with QSBS well in advance of an exit, and stack exclusions across the trusts. State of trust situs matters — putting a non-grantor trust in California defeats the strategy on the state side.

Stacking requires careful gift-tax planning, valuation discipline at the time of transfer, and a real (not paper) transfer of beneficial ownership. The IRS scrutinizes step-transaction issues when transfers happen too close to a known liquidity event.

Section 1045: The Rollover Safety Valve

If you sell QSBS before reaching the five-year hold (or, for post-OBBBA shares, before the tier you need), Section 1045 allows you to roll the proceeds into new QSBS within 60 days and defer the gain. Your holding period in the original stock tacks onto the replacement stock, so the rollover can preserve a path to eventual exclusion.

Practical uses: a founder whose company is acquired four years in, an early investor whose company is rolled up before year five, or anyone facing a forced exit short of the holding-period finish line. The replacement stock must itself meet the QSBS tests at acquisition.

Common Pitfalls

1. Significant redemptions. If the company redeems more than a de minimis amount of stock from related parties within a two-year window of your issuance (or within one year for unrelated parties for redemptions exceeding 5% of value), your stock can lose QSBS status entirely. Founders running secondary tender offers or buying out early employees need to model the QSBS impact before signing.
2. S-corp or LLC start. If your company began life as an LLC or S-corp and converted to a C-corp later, your QSBS holding period and basis begin at conversion — not at original formation. The pre-conversion appreciation is generally outside QSBS.
3. Share class changes. Recapitalizations, preferred-to-common conversions, and stock splits can affect QSBS status. Most do not break it, but some do. Document every recap and have your tax advisor review it contemporaneously.
4. Gross assets timing. The $75 million test is measured immediately before and after issuance. A late-stage convertible note or SAFE that converts at a moment when assets briefly spike can disqualify the issuance. Pay attention to bridge-round timing.
5. Missing the §1202 letter. The IRS does not require a formal letter, but documenting QSBS eligibility at issuance (gross assets at the time, active trade or business, qualifying use of proceeds) makes the exit-time tax filing far cleaner. Request a §1202 representation letter from the company at every round you participate in.
6. Assuming consulting or services businesses qualify. Pure consulting, accounting, legal, health, brokerage, and finance businesses are explicitly disqualified. Hybrid businesses (a SaaS product with a services arm) generally still qualify if the active trade or business test is met on the 80% asset standard, but the line is fact-specific.

Action Items for Founders

• Track basis from day one. Save your incorporation documents, your subscription agreement, the cancelled check for your founder shares, and every subsequent round's documents. Five years from now you will need them.
• Get a QSBS representation letter at every round. Even if your investors do not require it, request one from the company. Save it.
• Model the stack before you need it. If your expected exit will exceed $15 million in gain, talk to a tax professional 18 to 24 months before any anticipated liquidity event. Last-minute trust funding rarely works.
• Plan for California. If you live in California, the federal QSBS exclusion does not eliminate your state tax. Decide early whether residency change, trust planning, or simply paying the state tax is your strategy.
• Don't redeem first, ask later. If the company is considering a tender offer, buyback, or large secondary, run the QSBS impact analysis before the transaction.

When to Talk to Us

QSBS planning is one of the highest-leverage areas in tech founder tax. A founder with a $50 million exit and proper planning can save $7 to $10 million in federal tax. A founder without it pays full freight on the entire gain. The difference is almost entirely about decisions made years before the wire hits.

At Silicon Valley Tax, we advise founders, early employees, and angel investors on QSBS eligibility, holding-period optimization, gift and trust stacking, §1045 rollovers, and the California planning that surrounds all of it. If you are at a startup with a credible path to a meaningful exit, the right time to start QSBS planning is now — not the quarter before the term sheet arrives.

Schedule a free consultation and we will walk through your specific QSBS posture, the holding-period math for your shares, and whether stacking or California planning makes sense for your situation.