QSBS After OBBBA: A Founder's Guide to the §1202 Capital Gains Exclusion

What QSBS is and why it matters

Internal Revenue Code Section 1202 — Qualified Small Business Stock (QSBS) — allows eligible founders, employees, and investors to exclude federal capital gains tax on the sale of qualified C-corporation stock, up to a per-issuer limit. For founders of qualified startups, QSBS is one of the most valuable provisions in the Internal Revenue Code.

The five eligibility tests

1. Domestic C corporation. The issuing company must be a U.S. C corporation at the time of issuance and during substantially all of the holding period. S corporations and LLCs do not qualify.
2. Original issuance. The shareholder must acquire the stock directly from the company in exchange for cash, property other than stock, or services. Stock acquired on the secondary market does not qualify.
3. Gross-asset test. Aggregate gross assets must not have exceeded the statutory cap immediately before and immediately after issuance.
4. Active business test. At least 80% of the company's assets must be used in a qualified active trade or business. Excluded businesses include health services, law, financial services, brokerage, consulting, hospitality, farming, mining, and most investment activities.
5. Holding period. The shareholder must hold the stock for the required minimum period before sale.

OBBBA changes effective July 4, 2025

The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made the most significant changes to QSBS since the original enactment. The legislation applies to QSBS issued on or after July 4, 2025; pre-OBBBA stock continues to be governed by the prior rules.

Stacking and packing — multiplying the exclusion

The per-issuer cap is per taxpayer, not per company. Two strategies operate around this fact:

Stacking

Gifting QSBS shares to non-grantor trusts for the benefit of family members creates additional taxpayers, each with its own per-issuer cap. A family with a spouse and three non-grantor trusts can theoretically multiply the exclusion by five.

Packing

Contributing appreciated property (e.g., intellectual property, equipment, real estate) to the corporation in exchange for QSBS at issuance increases the basis of the stock. Because the per-issuer cap is the greater of the dollar cap or 10× basis, packing raises the 10× basis ceiling — the binding constraint for high-value exits.

Section 1045 rollover

If QSBS is sold before the holding period is met, IRC Section 1045 allows the proceeds to be rolled into replacement QSBS within 60 days, deferring the gain and tacking the holding period of the original stock to the replacement. This is a critical rescue path when a founder is forced into an early sale.

Documentation that must exist before exit

• Articles of incorporation showing C-corporation status from issuance.
• Board minutes and stock issuance records confirming original-issuance receipt.
• Audited or reviewed balance sheets at issuance to evidence the gross-asset test.
• Annual evidence (revenue split, payroll allocation, asset use) supporting the 80% active business test.
• Stockholder representation letters from the company at issuance and at sale.

Common mistakes that disqualify

• Operating as an LLC for the first year, then converting to a C-corp — basis at conversion is what matters, not founder dollars.
• Crossing the gross-asset cap on a single financing round (cash on the balance sheet counts).
• Drifting into an excluded business line (e.g., a fintech that becomes a "financial services" company under IRS guidance).
• Failing the 80% active business test by parking proceeds in marketable securities for too long.
• Selling at year four with no Section 1045 rollover and no tiered-exclusion qualification.

Pre-exit QSBS checklist

1. Confirm issuance date and which OBBBA regime applies to each tranche.
2. Calculate per-tranche holding period and exclusion percentage.
3. Identify per-issuer cap binding constraint — dollar cap vs. 10× basis.
4. Evaluate stacking — establish non-grantor trusts at least 12 months before LOI.
5. Order a QSBS opinion letter from outside tax counsel before signing the LOI.
6. Coordinate with the cash balance plan and Roth conversion plan — the year of sale is rarely the year of lowest marginal cost.