When a founder sells a company, federal capital gains, NIIT, and California tax can consume a large share of the proceeds. Section 1202, the qualified small business stock exclusion, can reduce the federal layer when the stock actually qualifies. It is a stock-sale provision. It is not a general rule for asset sales, and it is not a promise of zero tax.
What changed after July 4, 2025
For qualifying stock acquired after July 4, 2025, federal Section 1202 currently provides:
- 50 percent exclusion after 3 years
- 75 percent exclusion after 4 years
- 100 percent exclusion after 5 years
- a $15 million per-issuer limitation
- a $75 million aggregate-assets test for stock issued after that date
Stock issued under prior law remains subject to the rules in effect at issuance. Language that treats $10 million, $50 million, and a single five-year hold as the universal current regime is out of date.
What still has to be true
QSBS still requires original-issue C-corporation stock, an active trade or business under the statute, and a holding period that matches the applicable exclusion percentage. Construction, professional services, and certain other activities may fail the active-business test. Most pass-through owners need a conversion runway before any stock is issued.
QSBS generally applies to the sale or exchange of qualifying stock, not to an asset sale.
The California layer
California does not conform to Section 1202. A federal exclusion does not wipe California tax. Founders who model only the federal result can still owe a full California layer on the same gain.
Limitation stacking is fact-specific
Per-taxpayer limitations and trust or family transfers are planning tools, not a guaranteed way to clear an entire gain. The IRS looks at economic substance. We model the limitation that actually applies to the shares in the file, including legacy vs post-July 4, 2025 stock.
Timing
QSBS planning does not work after close. Holding-period clocks and original-issuance facts have to exist before the LOI. If you are three to five years from a possible exit, this is the window to audit issuance records, basis, and California exposure.
Most of the leverage is pre-LOI: testing whether the stock actually qualifies, under which vintage of the statute, and what California still takes.
How we work it
On exit files we audit issuance and basis, test the active-business rules, separate federal and California, and coordinate with M&A counsel so a stock deal is not converted into an asset deal that drops QSBS on the floor.
If you hold C-corp stock and a sale is on the horizon, the Assessment is the place to check vintage, holding period, and California, not the closing table.
This article is for general informational purposes only and does not constitute tax, legal, or investment advice. Business owners should consult qualified tax and legal advisors before entering into a transaction.
