Section 1202 of the Internal Revenue Code is, for founders and early-stage investors, often the largest single tax benefit available in the United States. Held correctly for the requisite period, qualified small business stock (QSBS) lets a non-corporate holder exclude up to the greater of $10 million or 10x basis of capital gain on the sale of that stock. For a successful exit, the math frequently runs into eight figures of saved federal tax. The mechanics, though, are exacting, and the recurring losses we see in practice are almost always traceable to a structural decision made years before the gain was ever realized.
This insight walks through the operative requirements of Section 1202, the related rollover provision in Section 1045, and the planning points that come up most often in venture-formation engagements.
The Core Exclusion
Under 26 U.S.C. § 1202(a), a taxpayer other than a corporation may exclude from gross income a percentage of the gain from the sale or exchange of qualified small business stock held for more than five years. For QSBS acquired after September 27, 2010, the exclusion is 100 percent of the eligible gain, subject to the per-issuer-per-shareholder cap.
The cap, set out in 26 U.S.C. § 1202(b)(1), is the greater of:
- $10 million, reduced by the aggregate amount of eligible gain taken into account in prior taxable years on dispositions of QSBS issued by the same corporation, or
- 10 times the aggregate adjusted bases of QSBS issued by the corporation and disposed of by the taxpayer during the taxable year.
For a founder who acquired stock at par for very low basis, the $10 million prong is what controls. For a sponsor or institutional investor who put real money in, the 10x basis prong can produce a much larger exclusion. The taxpayer takes the greater of the two on a per-issuer basis.
Section 1202 has a separate carve-out from the alternative minimum tax preference for the excluded gain on stock acquired after September 27, 2010, and the excluded gain is also exempt from the 3.8 percent net investment income tax under Section 1411. The headline percentage is therefore the after-tax percentage; there is no quiet AMT clawback to rebuild the exposure.
Issuer-Level Requirements
Stock qualifies as QSBS only if the issuer meets a structural test that runs both at issuance and substantially throughout the taxpayer's holding period.
Domestic C-corporation
Under 26 U.S.C. § 1202(c)(1), the issuer must be a domestic C-corporation. LLCs taxed as partnerships, S-corporations, and most foreign entities cannot issue QSBS. A common path is to form as an LLC for early operating flexibility and convert to a C-corporation later, but the conversion has consequences for the QSBS holding period: the stock issued at conversion is treated as issued at conversion (not at LLC formation), so the five-year clock starts fresh. Where preserving QSBS treatment matters, forming as a C-corporation at the outset is materially simpler than retrofitting it.
Gross-asset cap of $50 million
Under 26 U.S.C. § 1202(d)(1), the issuer must have aggregate gross assets of $50 million or less at all times before and immediately after the issuance. "Gross assets" means cash plus the adjusted bases of other property, with contributed property valued at fair market value rather than the basis the property had in the contributor's hands. The cap is on assets, not on enterprise value: a company with $30 million of paid-in capital and a $1 billion enterprise value still passes if the cash and other assets are $30 million.
The cap is measured at every issuance. Once the company first crosses $50 million in gross assets, stock issued after that point is no longer QSBS, but stock that was QSBS at issuance does not lose its status because the company later grows past the cap.
Active-business requirement
Under 26 U.S.C. § 1202(e), during substantially all of the taxpayer's holding period, the issuer must use at least 80 percent of its assets by value in the active conduct of one or more qualified trades or businesses. Working capital and assets held for two years or less in connection with reasonably anticipated research, R&D, or business needs count toward the 80 percent.
The principal trap here is investments. A company that accumulates significant cash and parks it in marketable securities for an extended period can fail the active-business test as the cash exceeds two-year working-capital reasonableness. Late-stage companies with large balance sheets sometimes lose QSBS status not because the operating business changed but because the treasury function did.
Excluded businesses
Under 26 U.S.C. § 1202(e)(3), certain businesses are categorically excluded:
- Any trade or business involving the performance of services in health, law, engineering, architecture, accounting, actuarial science, performing arts, consulting, athletics, financial services, brokerage services, or any trade or business where the principal asset is the reputation or skill of one or more employees.
- Banking, insurance, financing, leasing, investing, or similar business.
- Farming (including raising or harvesting trees).
- Any business involving the production or extraction of products of a character with respect to which a deduction is allowable under Sections 613 or 613A (oil, gas, coal, certain minerals).
- Hotel, motel, restaurant, or similar business.
The "consulting" prong has produced the most litigation and the most uncertainty, particularly for software-as-a-service businesses that include implementation or customer-success components. The IRS and Tax Court have generally focused on whether the principal value of the business is in deliverable software/IP versus in advice or services. Founders in adjacent categories (fintech with broker-dealer affiliates, marketplace businesses with insurance components) need a deliberate Section 1202 analysis at formation.
Holder-Level Requirements
To claim the exclusion, the taxpayer must be a non-corporate holder, must have acquired the stock at original issuance (directly or through an underwriter), and must hold it for more than five years.
Original issuance
Under 26 U.S.C. § 1202(c)(1)(B), the stock must have been acquired by the taxpayer at its original issue, in exchange for money, other property (not including stock), or as compensation for services provided to the issuer. Stock purchased on a secondary market does not qualify, with limited exceptions (stock received by gift or inheritance can tack on the donor's holding period and QSBS character; stock received in a Section 351 contribution or a tax-free reorganization may have special treatment under Section 1202(h)).
Holding period
Under Section 1202(a), the stock must be held for more than five years. The clock starts on the date of issuance. For a founder who issued and filed an 83(b) election on January 15, 2026, the earliest QSBS-eligible sale is January 16, 2031. There is no concept of an averaging or weighted-average holding period; each tranche is measured separately.
Section 1045 Rollover
The most-overlooked provision in early-stage tax planning is 26 U.S.C. § 1045. Section 1045 allows a non-corporate taxpayer who has held QSBS for more than six months but less than five years to elect to defer the gain by rolling the proceeds into replacement QSBS within 60 days of the sale.
The mechanics:
- The taxpayer sells QSBS held more than six months. The gain is otherwise immediately taxable because the five-year period is not yet met.
- Within 60 days of the sale, the taxpayer reinvests an amount equal to or greater than the proceeds in replacement QSBS issued by a different qualifying issuer.
- The taxpayer files an election under Section 1045 with the return for the year of sale.
- The gain is deferred to the replacement stock. The taxpayer's holding period in the original stock tacks onto the replacement stock for purposes of meeting Section 1202's five-year requirement.
For founders sitting on a year-four acquisition offer, Section 1045 is the answer to the question, "do I have to take the full tax hit if I sell now?" Provided the proceeds can be redeployed into another QSBS-eligible company within 60 days, the answer is no. The replacement stock then runs to its own five-year mark, with the prior holding period tacked on, and the eventual qualifying sale produces the same Section 1202 exclusion that would have been available on a year-five-plus sale of the original stock.
Section 1244 as the Downside Counterpart
The often-missed companion to Section 1202 is 26 U.S.C. § 1244, which lets a non-corporate holder of stock in a domestic small business corporation treat up to $50,000 of loss on the stock as ordinary loss rather than capital loss ($100,000 on a joint return). Because ordinary losses can be deducted against ordinary income at much higher marginal rates than capital losses can be used, the asymmetry is meaningful: capital gain on a successful exit (Section 1202), ordinary loss on a failure (Section 1244).
The election is structural (the corporation issues stock under a Section 1244 plan) and costs essentially nothing to set up at formation. It is a recurring missed opportunity to fail to do so.
Where Founders Most Often Go Wrong
Five recurring losses we see in venture-formation engagements:
- Forming as an LLC and converting to a C-corporation at financing. The conversion restarts the five-year clock for the stock issued at conversion. A founder who operated as an LLC for 18 months and converts at the seed round is now sitting in year zero of a five-year QSBS clock, not year 1.5. Where QSBS treatment matters, formation as a C-corporation from the outset is the right call.
- Operating in a Section 1202(e)(3) excluded line of business. Most common in fintech (financial services / brokerage), consulting-heavy SaaS (consulting), and crypto exchange businesses (financial services / brokerage). A deliberate analysis at formation is the difference between a $10 million federal-tax-free exit and a $10 million federal-tax-burdened exit on the same dollar.
- Crossing $50 million in gross assets before key issuances. The Section 1202(d) cap is measured at issuance, on aggregate gross assets. Stock issued after the company first crosses the cap is not QSBS, even if the stock issued before the cap remains QSBS forever. Companies in the late-stage growth band sometimes issue secondary stock to employees that could have been QSBS, had it been issued earlier.
- Failing to file 83(b) on unvested founder stock. If the stock is subject to vesting and no Section 83(b) election is made within 30 days, the stock is not "issued" for QSBS purposes until it vests. The QSBS holding period therefore begins on the vesting date of each tranche, not on the original grant date. The fix is to file 83(b) timely, which both produces ordinary-income consequences at $0 (for stock issued at fair value) and starts the QSBS clock at issuance.
- Selling at year four without a Section 1045 rollover. A year-four sale that could have been a Section 1045-deferred rollover into replacement QSBS instead becomes a fully taxable gain. The 60-day reinvestment window is short, but the planning happens before the sale closes, not after.
Planning at Formation
QSBS is not a tax election made at sale. It is a structural condition that runs from formation through the eventual exit. The decisions that determine QSBS eligibility are made when the company is incorporated, when founder stock is issued, when 83(b) elections are filed (or missed), when the company first issues stock at scale, and at any point the active-business test could break.
For founders building toward an exit five-plus years out, the structural QSBS analysis at formation is the highest-expected-value tax planning available. The same analysis applies to angel and seed investors, who have their own per-issuer $10 million / 10x basis cap and run their own holding-period clock.
For background on how QSBS planning fits into the broader formation architecture (entity choice, founder equity, IP assignment, financings, and governance), see our long-form guide on Setting Up a Venture: Formation, Capitalization, and Term Sheets.