This FAQ answers common October 2026 tax questions for startup founders about equity, deadlines, and credits. It gives practical rules for QSBS, restricted stock, stock options, valuations, quarterly payments, and research credits.
Qualified Small Business Stock means stock in a qualifying small C-corporation that can qualify for federal gain exclusion. Choices made at formation and grant affect taxes years later. Early paperwork often matters more than later planning.
Table of Contents
- How does QSBS work for founders now?
- Should you file an 83(b) election for restricted stock?
- What happens when you exercise incentive stock options?
- How do you price options and pay taxes on time?
- Can pre-profit startups use R&D credits?
How does QSBS work for founders now?
According to SDO CPA in its 2026 C-Corporation Tax Guide, QSBS issued after July 4, 2025 gets tiered exclusions by holding period. The schedule is 50% after three years, 75% after four years, and 100% after five years. The cap is $15 million per issuer and applies only to qualifying C-corporation stock. Congress.gov records show the One Big Beautiful Bill Act (P.L.
119-21) was signed July 4, 2025. That law raised the gross-asset eligibility threshold from $50 million to $75 million. Entity choice controls eligibility from day one. A founder who incorporates as a C-corporation, documents issuance dates, and tracks holding periods preserves the exclusion path. A later conversion does not fix early ineligible issuances.
Should you file an 83(b) election for restricted stock?
Restricted stock is stock subject to vesting or forfeiture. The founder is normally taxed as shares vest, often at higher values. An 83(b) election taxes the grant value now instead. According to the IRS in its update to Publication 525 for Section 83(b), the election is due no later than 30 days after transfer. It elects to recognize income at grant value, is irrevocable without IRS consent, and has no extension.
A founder who receives low-value founders' shares and files on time pays tax on a small amount now. The same founder who misses day 30 loses the choice and faces tax as later tranches vest. File even when grant value is near zero. Keep proof of timely mailing and a copy with your return files. Confirm the company records the election.
What happens when you exercise incentive stock options?
An incentive stock option, or ISO, is an employee option with special tax treatment. Exercising it produces no regular-tax income at exercise. The bargain element, meaning fair market value minus strike price, must generally be added to Alternative Minimum Taxable Income on Form 6251, according to the IRS Instructions for Form 6251 for 2025, posted Jan. 16, 2026. Savant Wealth Management reports that for 2026 the One Big Beautiful Bill Act retained higher AMT exemptions, $90,100 single and $140,200 joint per IRS, but lowered phaseout thresholds and doubled the phaseout rate to 50%.
More ISO exercises can therefore trigger AMT. Founders should model exercises before acting. A small early exercise may create little AMT pressure. A large exercise after a valuation jump can create a bill with no cash sale to pay it. Spread exercises across years, check cash needs, and keep Form 6251 in the plan.
How do you price options and pay taxes on time?
A private-company option priced below fair market value can violate Section 409A. The IRS notes in its Frequently Asked Questions on Section 409A and Deferred Compensation that a reasonable valuation is required, typically an independent 409A appraisal updated within 12 months. Failure causes current taxation plus a 20% additional income tax. Use a current appraisal to set the strike price.
Update it after material events and at least every 12 months. Do not backdate grants or reuse an old report after growth. Self-employed founders and pass-through owners also must pay as they go. According to IRS second-quarter and third-quarter tax calendars in its third-quarter tax calendar, 2026 quarterly estimated tax via Form 1040-ES is due on: The rule applies if you expect to owe $1,000 or more, or face underpayment penalties.
- April 15, 2026
- June 15, 2026
- September 15, 2026, plus January 15, 2027
Can pre-profit startups use R&D credits?
Yes, in some cases through payroll tax. The Section 41 research credit rewards qualified research spending. Pre-profit founders often have no income tax to offset. According to the IRS in its research credit against payroll tax, eligible startups can elect to apply up to $500,000 of the credit against payroll tax for tax years beginning after Dec. 31, 2022.
The election is made by filing Form 6765 with a timely return. It helps pre-profit founders monetize R&D spending. Track wages, supplies, and contract research tied to qualified work. File Form 6765 with the timely return, not on an amended claim later. Add Form 6765 to your timely filed return checklist now, while payroll records are complete.