QSBS Section 1202: How to Exclude Up to $15M in Capital Gains

The Biggest Tax Break Most Startup Employees Do Not Know About

Section 1202 of the Internal Revenue Code — the Qualified Small Business Stock (QSBS) exclusion — allows eligible stockholders to exclude up to $15 million (or 10x their cost basis, whichever is greater) in capital gains from federal taxation when they sell qualifying shares. For startup employees who exercise stock options early and hold their shares, this can mean paying zero federal capital gains tax on a multi-million dollar exit.

The QSBS exclusion is the single most powerful tax planning tool available to startup employees, yet it is widely underutilized because many employees do not know it exists or do not understand the requirements.

The 2025 OBBBA Changes

The One Big Beautiful Bill Act (OBBBA), signed into law in 2025, made significant changes to the QSBS exclusion:

Increased Exclusion Cap

The maximum exclusion was increased from $10 million to $15 million per issuer. This means eligible stockholders can exclude up to $15 million in capital gains from federal tax.

Increased Gross Asset Limit

The maximum gross asset threshold was raised from $50 million to $75 million. A company qualifies as a "qualified small business" if its aggregate gross assets have never exceeded $75 million at any time before and immediately after the stock issuance.

Graduated Exclusion Schedule

The OBBBA introduced a graduated exclusion based on holding period:

Previously, the exclusion was a flat 100% for stock held at least 5 years. The new graduated schedule creates partial benefits for shorter holding periods, but the full 100% exclusion still requires 5+ years of holding.

Eligibility Requirements

To qualify for the QSBS exclusion, all of the following must be true:

1. C-Corporation Stock

The company must be organized as a C-corporation (not an LLC, S-corp, or partnership) at the time the stock is issued and during substantially all of the holding period. Most venture-backed startups are C-corps.

2. Active Business Requirement

The corporation must use at least 80% of its assets in the active conduct of one or more qualified trades or businesses. Certain industries are excluded: professional services (law, accounting, consulting, health), financial services, mining, hospitality, and farming.

Most technology companies qualify. Service businesses generally do not.

3. Gross Assets Under $75M

The company's aggregate gross assets must never have exceeded $75 million at any time before and immediately after your stock was issued. Gross assets include cash received from stock issuances. Once the company crosses this threshold, stock issued afterward does not qualify — but stock issued before the threshold was crossed may still qualify.

4. Original Issuance

You must have acquired the stock at original issuance — directly from the company, not from another stockholder on a secondary market. Stock acquired through exercising stock options qualifies, as does stock received through RSU vesting (subject to certain conditions). Stock purchased on the secondary market does not qualify.

5. Holding Period

Under the new graduated schedule, you must hold the stock for at least 3 years for any exclusion (50%), with the full 100% exclusion requiring 5 years from the date of acquisition (exercise date for stock options).

How It Works in Practice

Example

You exercise ISOs at a startup:

• Exercise price: $1 per share
• Number of shares: 100,000
• Total cost: $100,000
• 10x basis exclusion: $1,000,000

Five years later, the company goes public and you sell:

• Sale price: $50 per share
• Total proceeds: $5,000,000
• Capital gain: $4,900,000

If QSBS applies:

• Federal tax on the gain: $0 (the $4.9M gain is below both the $15M cap and the 10x basis of $1M)
• Savings: Approximately $1.16M in federal capital gains tax (at 23.8% including NIIT)

The 10x Basis Rule

The exclusion is the greater of $15 million or 10x your adjusted basis in the stock. If your cost basis is $2 million, your 10x exclusion is $20 million — which exceeds the $15M cap, so you get $20 million of exclusion. This benefits employees with larger exercise costs.

State Conformity

This is critical: Not all states follow the federal QSBS exclusion.

California is the biggest issue: California does not recognize the QSBS exclusion at all. Even if you pay zero federal tax on a $10 million QSBS gain, you still owe California up to 13.3% ($1.33 million). For California-based startup employees, this is a significant planning consideration.

Strategies for Maximizing QSBS Benefits

Exercise Early

The QSBS holding period begins on the date you acquire the stock (exercise date). Exercising early — ideally when the spread is small — starts the clock sooner. If you exercise at the time of your grant and hold for 5+ years, you maximize both the holding period and the tax benefit.

File an 83(b) Election

If you early exercise unvested shares, filing an 83(b) election starts both the QSBS holding period and the capital gains holding period immediately. Without the 83(b) election, the QSBS clock may not start until vesting.

Per-Issuer Limit

The $15M exclusion is per issuer, per taxpayer. If you and your spouse both hold QSBS in the same company and file jointly, you may each claim up to $15M of exclusion — for a combined exclusion of up to $30M. However, this requires proper structuring and advice from a tax professional.

Gifting Strategies

QSBS stock can be gifted to family members, trusts, or other entities, with each recipient potentially claiming their own QSBS exclusion. This is an advanced strategy that requires careful legal planning.

Common Pitfalls

Secondary Market Sales Break QSBS

If you sell QSBS shares and then use the proceeds to buy shares from another holder, the new shares do not qualify for QSBS (they were not acquired at original issuance).

Company Becoming Too Large

If the company's gross assets exceeded $75M before your stock was issued, your shares do not qualify regardless of when you acquired them. Check with your company's finance team.

Insufficient Holding Period

The graduated schedule means even a partial QSBS benefit requires at least 3 years of holding. Selling before 3 years means zero QSBS exclusion.

The Bottom Line

QSBS is the most valuable tax benefit available to startup employees — potentially saving millions in federal taxes. The combination of early exercise, 83(b) election, and holding for 5+ years creates the maximum benefit. But eligibility is technical, state conformity varies, and the stakes are high enough to justify working with a tax professional who specializes in equity compensation.