QSBS Rules Changed in 2026: What Founders and Physicians Need to Know

If you own a startup or a medical practice organized as a C corporation, the Qualified Small Business Stock exclusion just got better. The cap jumped from $10 million to $15 million. But there's a catch that most people are missing.

I work with tech founders and physicians who sell businesses or practices. The question always comes up: how much can I shelter from capital gains taxes? For years, the answer was $10 million under Section 1202. That changed in July 2025 with the One Big Beautiful Bill Act, and the rules are fully in effect for 2026.

Here's what changed, what stayed the same, and the planning moves you need to make before it's too late.

What Is QSBS and Who Qualifies?

Qualified Small Business Stock lets founders and early employees exclude capital gains when they sell C corporation stock held more than five years. The exclusion applies to federal taxes. Some states conform, some don't.

To qualify, the corporation must meet these tests:

Domestic C corporation (not S corp, not LLC)
Gross assets under $75 million before and immediately after stock issuance (raised from $50 million)
Active business requirement (at least 80% of assets used in qualified trade or business)
Stock issued at original issuance (not bought on secondary market)
Held for required holding period (see below)

Most tech startups qualify. Most physician practices organized as C corps qualify. Professional service businesses like health, law, and consulting have limitations, but there are structures that work.

The 2026 Changes: Three Big Shifts

1. Exclusion Cap: $10M to $15M

The lifetime exclusion limit per issuer jumped 50 percent. If you sell qualified stock issued after July 4, 2025, you can exclude up to $15 million in gains. That's indexed for inflation starting in 2027, so expect it to creep higher.

For context, at a 20 percent long-term capital gains rate plus 3.8 percent NIIT, sheltering $15 million saves roughly $3.5 million in federal taxes. Realistically, that's life-changing money for most founders.

2. Tiered Holding Periods (New)

This is the big planning angle. The old rule was binary: hold five years, get 100 percent exclusion. The new rules create three tiers for stock issued after July 4, 2025:

Hold 3+ years: 50 percent exclusion
Hold 4+ years: 75 percent exclusion
Hold 5+ years: 100 percent exclusion

Why does this matter? Because not every founder can wait five years. Some get acquisition offers at year three. Some need liquidity earlier. Now you have options.

Let's say you have $10 million in gains. Under old rules, selling at year three meant zero exclusion. Now you exclude $5 million. At year four, you exclude $7.5 million. At year five, all $10 million.

3. Gross Asset Threshold: $50M to $75M

The corporation can have up to $75 million in gross assets at stock issuance and still qualify. This lets later-stage companies still issue QSBS-eligible stock to employees and investors.

The Two-Regime Strategy: Sell Old Stock First

Here's the planning move most advisors are missing. You have two regimes now:

Pre-July 4, 2025 stock: Old rules apply. Five-year hold, $10 million cap, 100 percent exclusion only.

Post-July 4, 2025 stock: New rules apply. Tiered holding periods, $15 million cap.

If you hold both vintages, sell the pre-OBBBA stock first. Maximize the $10 million exclusion under old rules. Then let the newer stock continue toward the tiered milestones.

I had a founder call me last month with exactly this situation. He had stock from 2020 and fresh issuance from late 2025. The math worked like this:

Sell 2020 stock first: shelter up to $10 million at 100 percent
Hold 2025 stock: target the $15 million cap with tiered flexibility

Doing it backwards would have left money on the table. Right?

State Tax Trap: California, Pennsylvania, and Others

Not all states conform to federal QSBS rules. California, Alabama, Mississippi, and Pennsylvania tax QSBS gains at full state rates even when federal exclusion applies.

If you're a California founder or physician, the federal exclusion still saves you 23.8 percent (20 percent LTCG plus 3.8 percent NIIT). But you'll owe California state tax on the gain. The planning move here is either relocate before sale or factor the state tax into your net proceeds.

Texas founders have a clean shot: 0 percent combined tax with federal exclusion and no state income tax.

Physicians Who Own Practices: This Applies to You Too

Emergency medicine groups, radiology practices, dermatology clinics, psychiatry telehealth platforms. Many organize as C corporations. Many plan to sell to private equity or hospital systems.

If your practice is a C corp with gross assets under $75 million, your stock likely qualifies. The $15 million exclusion applies the same way as for tech founders.

The specialty-specific angle: neurology, cardiology, gastroenterology practices often hit valuations where the exclusion cap matters. A $20 million practice sale with $15 million excluded means you're taxed on $5 million instead of the full amount.

Common Mistakes I See

1. Missing the 5-Year Hold

The exclusion only works if you hold the stock more than five years for 100 percent exclusion. Selling at year four under old rules meant zero benefit. The new tiered rules help, but you still need to track the clock.

2. S Corp or LLC Structure

QSBS only applies to C corporations. Many professional practices elect S corp status for pass-through taxation. That disqualifies QSBS treatment. There are conversion strategies, but they require advance planning.

3. Secondary Market Purchases

Stock must be issued at original issuance from the corporation. Buying shares from another shareholder on the secondary market doesn't qualify. Founders and early employees typically qualify. Later hires buying from early exits typically don't.

4. Professional Service Limitations

Section 1202 excludes certain professional service businesses: health, law, engineering, architecture, accounting, actuarial science, performing arts, consulting, athletics, financial services, brokerage services.

But there's a workaround. Many practices operate through a management services organization (MSO) structured as a C corp that provides non-clinical services. The MSO stock can qualify even if the clinical entity doesn't.

Planning Timeline: Start 12 to 24 Months Before Sale

QSBS planning isn't last-minute work. You need to:

Confirm C corp status and asset thresholds
Track issuance dates for each stock grant
Model tiered holding period scenarios
Coordinate with state tax strategy
Document qualified business activity

The best time to start is when you incorporate or raise capital. The second-best time is 12 to 18 months before an anticipated sale.

The Bottom Line

QSBS just got better for founders and practice owners selling businesses. The $15 million exclusion with tiered holding periods creates real planning flexibility. But the rules are specific, and the state tax traps are real.

If you're sitting on qualified stock, map out your vintage dates and holding periods now. Sell pre-OBBBA stock first. Let newer stock ride toward the tiered milestones. And factor in your state tax situation before you sign the purchase agreement.

It sounds complicated, but realistically, the planning is straightforward once you know the dates and the structure. The whole point is maximizing what you keep after the sale.

FAQ

Q: Does QSBS apply to S corporations or LLCs?

A: No. QSBS only applies to C corporations. S corps and LLCs are pass-through entities and don't qualify. Some practices convert to C corp status before sale to access QSBS, but this requires advance planning and tax analysis.

Q: What's the holding period for 100 percent exclusion?

A: For stock issued before July 4, 2025, you need five years. For stock issued after July 4, 2025, you get 50 percent at three years, 75 percent at four years, and 100 percent at five years.

Q: Can I stack exclusions across multiple companies?

A: Yes. The $10 million or $15 million limit is per issuer. If you have qualified stock from two different C corporations, you can exclude up to the cap for each one.

Q: Do California residents lose the QSBS benefit?

A: No, but California doesn't conform to federal QSBS rules. You still get the federal exclusion (saving 23.8 percent in federal taxes), but you'll owe California state tax on the gain. Planning moves include relocation before sale or factoring state tax into net proceeds.

Q: How do I confirm my stock qualifies?

A: Work with a tax advisor to confirm: C corp status, gross assets under $75 million at issuance, active business requirement, original issuance, and holding period. Documentation matters for IRS substantiation.

Malik is a financial advisor working with tech founders and physicians on equity compensation, practice sales, and tax-efficient wealth building. This post is educational and not tax advice. Consult your tax advisor for your situation.