QSBS & Founder Stock
QSBS can turn years of startup risk into one of the most consequential federal tax exclusions available to a founder or investor.
It can also disappear because of a fact buried years earlier in the company's history.
The wrong instrument. A late option exercise. A financing that pushed gross assets over the threshold. A business activity that falls outside Section 1202. A stock repurchase near issuance. An LLC conversion after the company became too valuable.
The useful question is not simply:
"Is this company QSBS?"
It is:
"Do these particular shares, in this taxpayer's hands, satisfy the Section 1202 chain?"
The rules changed in 2025
QSBS no longer has a single five-year story.
For qualifying stock acquired after July 4, 2025, federal law introduced a phased exclusion framework that can potentially provide:
- 50% exclusion after the applicable three-year period;
- 75% after four years;
- 100% after five years.
The per-issuer dollar limitation also changed for newer stock.
Separately, the qualified-small-business gross-assets threshold increased for stock issued after July 4, 2025.
That difference—acquisition date for some rules, issuance date for another—is one reason old QSBS summaries can now produce the wrong answer.
Start with the transaction, not the tax break
A defensible QSBS analysis follows a sequence.
What did you acquire? Stock? An option? A SAFE? A convertible note? An LLC interest?
How did you acquire the stock? Directly from the corporation? Through an option exercise? By gift? Through a partnership distribution?
Did the corporation qualify when the shares were issued? That brings in the gross-assets test and original-issuance rules.
What did the company do while you held the shares? The active-business requirement can continue through substantially all of the relevant holding period.
How long have the qualifying shares been held? That determines which exclusion percentage may be available.
How much gain is eligible? The per-issuer dollar limit and 10× basis alternative still matter.
The nine guides
QSBS After July 4, 2025: Which Holding-Period and Exclusion Rules Apply?
Covers legacy QSBS regimes, post-July 4, 2025 3/4/5-year treatment, $10 million versus $15 million limits, the 10× basis alternative, mixed acquisition dates, and legacy AMT treatment.
Does My Stock Qualify for QSBS? A Documentation Checklist
Covers evidence for original issuance, C-corporation status, gross assets, active-business compliance, Section 83(b), redemption history, transfers, and prior QSBS sales.
QSBS Original Issuance: Founder Stock, Employee Stock, and Option Exercises
Covers founder stock, restricted stock, Section 83(b), ISOs and NSOs, RSUs, SAFEs, convertible notes, secondary purchases, and redemption traps.
QSBS Gross-Assets Test: $50 Million vs. $75 Million
Covers the statutory asset calculation, issuance proceeds, contributed-property FMV, financing closings, controlled groups, predecessors, and later company growth.
QSBS Active Business Requirement: Which Businesses Qualify?
Covers excluded businesses, ambiguous technology/service businesses, startup activity, R&D, working capital, portfolio securities, subsidiaries, real estate, and business pivots.
QSBS and LLC-to-C-Corporation Conversions: Can the Stock Qualify?
Covers when C-corporation stock arises, pre-conversion LLC ownership, conversion forms, contributed-property FMV, simultaneous financing, Section 351, and documentation.
Gifts and Inherited QSBS: Do the Tax Attributes Carry Over?
Covers acquisition-manner and holding-period carryover, gift and inherited basis boundaries, trusts, pre-sale transfers, and assignment-of-income concerns.
QSBS Held Through a Partnership: When Can a Partner Use Section 1202?
Covers partner-at-acquisition requirements, continuous ownership, ownership changes, carried interests, distributions, contributions, and partnership Section 1045 mechanics.
Section 1045 Rollover: What If You Sell QSBS Before the Full Holding Period?
Covers the more-than-six-month rule, 60-day replacement period, partial/full reinvestment, basis reduction, holding-period coordination, and partnership rules.
What this hub does not turn into a formula
PRISM does not present aggressive multi-trust "QSBS stacking" as a mechanical strategy. Trust planning can implicate taxpayer identity, grantor-trust rules, completed gifts, assignment of income, step transaction, economic substance, and gift and estate tax.
State treatment should not be inferred from the federal result. State QSBS conformity belongs to the State & Multi-State Investment Tax section of the Atlas.
A practical QSBS sequence
- Identify the shares.
- Establish issuance and acquisition history.
- Prove original issuance or a statutory continuation rule.
- Reconstruct aggregate gross assets at issuance.
- Review the business throughout the holding period.
- Determine the applicable holding-period regime.
- Calculate the eligible-gain limitation.
- Check federal reporting and state treatment.
Where this becomes a professional question
QSBS deserves professional review when the potential exclusion is material and the position involves multiple stock blocks, old and new regimes, options or restricted stock, SAFEs or convertible instruments, an LLC conversion, contributed property, redemptions, gifts or trusts, partnership ownership, Section 1045, uncertain company records, or multi-state exposure.
Call PRISM — (917) 724-3965
Governing authorities
The core federal framework includes Internal Revenue Code §§1202 and 1045, related provisions governing basis, holding periods, compensation property, partnerships, and transfers, applicable Treasury regulations, and the 2025 amendments to Section 1202.