QSBS and Section 1202: Excluding Up to $10 Million in Capital Gains on Small Business Stock
Section 1202 of the Internal Revenue Code provides one of the most valuable tax benefits in the entire code: a 100% exclusion of capital gains on the sale of Qualified Small Business Stock (QSBS). A founder who meets all requirements can exclude up to $10 million in gain (or 10x their adjusted basis in the stock, whichever is greater) from federal income tax. For a startup founder who invested $500,000 and sells for $15 million, up to $10 million of the $14.5 million gain is tax-free.
QSBS requirements (ALL must be met):
- C-Corporation: The business must be a domestic C-Corporation. S-Corps, LLCs, partnerships, and sole proprietorships do NOT qualify. The stock must be issued directly by the corporation (not purchased on the secondary market). The C-Corp can convert to an S-Corp later without disqualifying the stock, as long as the stock was C-Corp stock when acquired.
- Original issuance: The taxpayer must have acquired the stock at original issuance in exchange for money, property (other than stock), or services. Stock purchased on the secondary market (from another shareholder) does NOT qualify, unless it was gifted or inherited from someone who held qualifying stock. Stock options count too, if exercised and held; the holding period starts at exercise, not at grant.
- $50 million gross assets test: At the time of stock issuance AND immediately after, the corporation’s aggregate gross assets (cash + adjusted basis of all property) must not exceed $50 million.
- Active business requirement: At least 80% of the corporation’s assets must be used in the active conduct of a qualified trade or business during substantially all of the taxpayer’s holding period.
- Excluded businesses: The corporation cannot be in: health, law, engineering, architecture, accounting, actuarial science, performing arts, consulting, athletics, financial services, brokerage, or any business where the principal asset is the reputation or skill of employees. Also excluded: banking, insurance, farming, mining, hospitality (hotels, restaurants, motels).
- 5-year holding period: The stock must be held for more than 5 years to qualify for the 100% exclusion.
- Exclusion amount: The greater of $10 million ($5 million for married filing separately) or 10x the adjusted basis of the stock. For stock acquired for services (basis = compensation income recognized), the basis is the amount included in income.
The OBBBA made the 100% exclusion permanent for stock acquired after September 27, 2010.
How much is the tax savings worth?
Stacking the exclusion through multiple shareholders
Each shareholder has their own $10 million exclusion. If the founder and their spouse each hold stock (acquired separately at original issuance), the combined exclusion is $20 million. If the founder also gifted stock to children (who hold it for 5+ years), each child has their own $10 million exclusion. This stacking strategy can shelter $30 million, $40 million, or more in total gain across the family.
Section 1045 rollover
If the founder sells before the 5-year mark, they can roll the gain into new QSBS within 60 days under IRC 1045. The 5-year clock restarts on the new stock, but the gain is deferred. This is useful when a founder exits one company early and reinvests in another qualifying C-Corporation.
What about S-Corp to C-Corp conversion for QSBS?
An S-Corp cannot issue QSBS. However, an S-Corp can revoke its S election and become a C-Corp. Stock held by shareholders at the time of conversion does NOT qualify as QSBS (it was not issued at original issuance by a C-Corp). Only new stock issued AFTER the conversion to C-Corp qualifies.
Some planning strategies involve converting to C-Corp and issuing new shares (through a recapitalization), but this is complex and must be structured carefully to avoid the IRS treating it as a sham transaction. This is an area where professional advice is essential before making the election.
For startups that expect to grow significantly and eventually sell, structuring as a C-Corp from the beginning preserves the QSBS benefit. The C-Corp’s 21% flat tax rate is a cost, but the potential $10 million tax-free gain on exit can dwarf the additional corporate-level tax paid during the holding period.
The S-Corp mistake: founders sometimes default to an S-Corp for the self-employment tax savings during operations, maybe $30,000 a year for a growing business. But if the business is headed toward a high-growth exit, that same choice can cost over a million dollars in tax at sale, since the gain never qualifies for the QSBS exclusion. For a business with a real exit plan, the C-Corp plus QSBS structure usually wins by a wide margin despite the double-taxation exposure along the way.
QSBS also only applies to the C-Corp period of a company’s life. If a business starts as an LLC (taxed as a partnership) and later converts to a C-Corp, the 5-year holding period starts at the conversion date, not at the LLC’s formation, and only stock issued as C-Corp stock qualifies. Deciding the entity structure at day one, rather than converting later, is the cleanest path to QSBS eligibility.
Related guides:
Start with a Diagnostic: a CPA licensed in the US and Canada reads your file and answers in writing, three to four business days after you finish the questions. $250 for cross-border, $195 for a second opinion on a filed return, and it comes straight off the bill if we do the work after. Or book a free 15-minute fit call first.
One or two plain-English guides a week on US-Canada tax. No spam, unsubscribe anytime.
Done. The next guide will land in your inbox.
Yarik Yarosh, CPA. "QSBS and Section 1202: Excluding Up to $10 Million in Capital Gains on Small Business Stock." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/small-business-qsbs-section-1202-exclusion
This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.