QSBS and OBBBA

For decades, forming a C-Corp was a binary bet on a specific timeline: The 5-Year Cliff.

Under the old rules, if you sold your company in Year 4 and 11 months, you received $0 in QSBS (Qualified Small Business Stock) benefits. You paid full taxes -- often double taxation -- without any of the reward.

The One Big Beautiful Bill Act (OBBBA), signed in July 2025, fundamentally changed this risk profile. By introducing a tiered vesting schedule and raising the exclusion cap, the legislation has made the C-Corp substantially less risky for founders who might exit early.

To see the practical impact, let's run a simulation for a hypothetical startup formed after August 1, 2025.

The Scenario

• Entity: A technology startup formed post-enactment (August 2025).

• The Exit: The founder sells the company for a $10 Million profit.

• The Comparison: We compare the Federal Tax Bill under three structures:

  1. LLC (Pass-Through): Taxed at standard Capital Gains rates (~23.8% incl. NIIT).
  2. Old C-Corp Rules: The pre-2025 "All or Nothing" rules.
  3. New C-Corp Rules (OBBBA): The new tiered exclusion and higher caps.

The Comparative Table: Federal Tax Liability on $10M Profit

Exit Timing	LLC (Pass-Through)	C-Corp (Old Rules)	C-Corp (New OBBBA)	The "New Rule" Advantage
Year 3.5	$2,380,000	$2,380,000	$1,190,000	Saves $1.2M vs. LLC
Year 4.5	$2,380,000	$2,380,000	$595,000	Saves $1.8M vs. LLC
Year 5+	$2,380,000	$0	$0	Saves $2.4M vs. LLC

Analysis of the Exits

Scenario A: The "Early" Exit (Year 3.5)

• The Old Problem: If you received an unsolicited offer after 3.5 years, the Old C-Corp rules punished you. You missed the 5-year window, so you paid full tax plus you likely dealt with corporate tax drag along the way.
• The New Reality: OBBBA introduces a 50% Exclusion for stock held between 3 and 4 years. Even though you sold early, you still cut your effective tax rate in half (from ~23.8% to ~11.9%).
• The Verdict: The C-Corp now beats the LLC even on a 3-year timeline.

Scenario B: The "Tweener" Exit (Year 4.5)

• The Old Problem: Selling just months before the 5-year mark used to be a tragedy. Founders would often try to delay deals to hit the deadline, sometimes killing the deal in the process.
• The New Reality: Stock held between 4 and 5 years now qualifies for a 75% Exclusion.
• The Verdict: You pay an effective federal rate of just ~6%. The "Risk of Ruin" for selling early has been effectively eliminated.

Scenario C: The "Grand Slam" (Year 5+)

• The Old Problem: The exclusion was capped at $10 Million. For a massive exit (e.g., $10M profit), you walked away tax-free, but any dollar over $10M was fully taxed.
• The New Reality: OBBBA raised the cap to $15 Million (indexed for inflation).
• The Verdict: The entire $10M gain is tax-free. And crucially, you have an extra $5 Million buffer for even larger exits before you pay a dime in federal tax.

The "Asset Cap" Buffer

There is one more structural advantage that isn't in the table but matters for growth.

• Old Rule: To issue QSBS, your company couldn't have gross assets over $50M.
• New Rule: The cap is raised to $75M.
• Practical Impact: You can now raise a significantly larger Series B or C round (up to $75M in gross assets) and still issue QSBS-eligible stock to new key hires. This allows you to keep your talent incentives tax-aligned for longer as you scale.

The Verdict: The Safe Zone Has Expanded

Before OBBBA, choosing a C-Corp was a gamble. You had to ask: "Am I 100% sure I will hold this for 5 years?" If the answer was no, the LLC was safer.

Now, the math has shifted.

• LLC: Still the correct choice for lifestyle businesses where you need immediate cash flow.
• C-Corp: Now the dominant choice for any company with a 3+ year horizon. The penalty for selling early (Years 3-5) has been reduced from "Total Loss" to "Partial Win."