QSBS and Section 1202 — How to Claim the Exclusion on Form 8949

You joined a startup early — a founder, or one of the first employees — took stock instead of a bigger salary, held on through the grind, and the company finally had a liquidity event. Now you're looking at a life-changing capital gain, and a 1099-B that treats it like any ordinary stock sale. What that 1099-B doesn't know is that your shares may qualify for one of the most generous breaks in the entire tax code: the Section 1202 exclusion for Qualified Small Business Stock.

If your shares are QSBS and you held them long enough, Section 1202 can let you exclude up to $10 million of gain — or 10 times your basis, whichever is greater — from federal tax entirely. But the exclusion doesn't happen automatically; the broker reports the full gain, and you claim the exclusion yourself on Form 8949 using adjustment code Q. Miss the reporting step and you hand the IRS tax on income Congress meant you to keep. This guide covers what qualifies and exactly how to claim it.

What Qualifies as QSBS

Section 1202 has strict requirements. To be Qualified Small Business Stock, the shares generally must meet all of these:

• C corporation stock. The issuer must be a domestic C corporation — not an S corp, LLC, or partnership.
• Acquired at original issuance. You must have received the stock directly from the company (for cash, property, or services), not bought it on the secondary market.
• $50 million gross assets test. The company's aggregate gross assets must have been $50 million or less immediately after the stock was issued.
• Active qualified business. At least 80% of the company's assets must be used in an active qualified trade or business. Certain fields are excluded — most professional services (law, health, consulting, finance), hospitality, and farming don't qualify.
• Holding period. You must have held the stock for more than five years to get the full exclusion.

Startups in tech, software, and product businesses are the classic QSBS candidates. Service firms and holding companies usually are not.

How Much You Can Exclude

For QSBS acquired after September 27, 2010 and held more than five years, you can exclude 100% of the eligible gain, up to the greater of:

• $10 million of gain (per taxpayer, per company), or
• 10 times your adjusted cost basis in the stock.

For most founders and early employees with a low basis, the $10 million cap is the binding number — and it's per company, so gains across multiple qualifying companies each get their own cap. Excluded gain is also generally exempt from the 3.8% net investment income tax.

A note on recent changes: 2025 legislation expanded QSBS for stock acquired after mid-2025, introducing a tiered exclusion (partial exclusion at three and four years, full at five), a higher per-issuer cap, and a raised gross-assets threshold. Stock acquired earlier follows the long-standing rules above. Because the rules now depend on when you acquired the shares, confirm which regime applies to your specific stock.

How to Report It on Form 8949 with Code Q

This is the mechanical heart of claiming the exclusion. You report the full sale and then back out the excluded gain as a negative adjustment:

1. Report the sale on Form 8949, Part II (long-term) — QSBS held over five years is always long-term. Use Box E if basis wasn't reported to the IRS, or Box D if it was.
2. Enter the proceeds (column d) and cost basis (column e) from your records, producing the full gain.
3. In column f, enter adjustment code Q (the code specifically for Section 1202 exclusions).
4. In column g, enter the excluded gain as a negative number. This subtracts the exclusion so only the taxable portion (if any) flows to Schedule D.

If your entire gain is under the cap and 100% excludable, column g zeroes out the gain entirely. Our Form 8949 adjustment codes reference shows code Q alongside the others, and the Form 8949 from 1099-B walkthrough covers the column layout end to end.

The Documentation You Need

Because the 1099-B won't reflect any of this, keep a paper trail proving the stock qualified:

• Proof of original issuance — your stock purchase agreement or grant showing you acquired directly from the company.
• Acquisition date and cost basis — to establish the five-year holding period and compute the 10x-basis cap.
• The company's QSBS attestation — many startups provide a letter or 83(b)/cap-table documentation confirming C-corp status and the gross-assets test at issuance. Request this from the company; it's your best evidence.

The IRS can challenge a 1202 exclusion, so the documentation matters as much as the reporting.

Common QSBS Mistakes

• Not claiming it at all because the 1099-B showed a normal taxable gain. The exclusion is opt-in via Form 8949 — silence means you pay full tax.
• Selling before five years. A day short of the five-year mark can forfeit the full exclusion. (A Section 1045 rollover into new QSBS can sometimes preserve it — worth exploring before you sell early.)
• Assuming S-corp or LLC equity qualifies. Only C-corp stock is eligible. Equity in a pass-through doesn't count, even if the company is small.
• Overlooking the per-company cap structure. The cap is per issuer, so gains from different qualifying companies aren't lumped under a single $10M limit.

FAQ

What is the Section 1202 QSBS exclusion?

A federal tax break that lets you exclude up to the greater of $10 million or 10 times your basis in gain from selling Qualified Small Business Stock held more than five years. For eligible stock, the exclusion can be 100%.

How do I claim QSBS on my tax return?

Report the full sale on Form 8949, Part II, then enter adjustment code Q in column f and the excluded gain as a negative number in column g. This removes the excluded portion from your taxable gain.

What stock qualifies for Section 1202?

Stock in a domestic C corporation with $50 million or less in gross assets at issuance, acquired directly from the company at original issuance, in an active qualified business, and held more than five years.

Does my 1099-B show the QSBS exclusion?

No. The broker reports the full gain as an ordinary stock sale. You claim the exclusion yourself on Form 8949 with code Q — it's easy to miss if you don't know to look for it.

What if I held the stock less than five years?

The full exclusion generally requires more than five years. Selling earlier can forfeit it, though a Section 1045 rollover into replacement QSBS may preserve the benefit. Recent 2025 rules add partial exclusions at shorter holding periods for newly acquired stock.

Is the excluded gain also free of the 3.8% net investment income tax?

Yes. Gain excluded under Section 1202 is generally also exempt from the 3.8% net investment income tax, compounding the benefit.

Bottom Line

Section 1202 is one of the biggest rewards in the tax code for taking startup equity risk — up to $10 million of gain (or 10x your basis) excluded from federal tax. But your 1099-B treats a QSBS sale like any other, so the entire benefit hinges on you claiming it correctly: report the full sale on Form 8949, then subtract the excluded gain with code Q in column g.

Confirm your shares meet every requirement, nail down the documentation, mind the five-year holding period, and check which rule set applies given when you acquired the stock. Get it right, and a seven- or eight-figure gain can land largely — or entirely — tax-free.

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Reconciling a big exit across multiple lots and grants? Convert your 1099-B free — we extract every transaction with proceeds, basis, and dates intact, so you can isolate your QSBS shares and build a clean Form 8949 before layering in the Section 1202 exclusion.