The 83(b) Election: Startup Equity's 30-Day Tax Window

Founders and early employees who receive restricted stock or exercise stock options early sit on one of the best tax opportunities in the code — and one of the tightest deadlines. Section 83(b) of the Internal Revenue Code lets you elect to pay income tax based on the current (low) fair market value of your equity rather than the much higher value it will have when it vests. The catch: you have exactly 30 days from the grant or exercise date to file. Miss the deadline and there are no extensions, no equitable exceptions, and no IRS relief.

The default rule: how Section 83 taxes equity compensation

Under the default rule of IRC § 83, compensatory property received subject to a "substantial risk of forfeiture" — meaning vesting conditions — is not taxed until those conditions lapse. For a typical 4-year vesting schedule with a 1-year cliff, that means:¹

• Year 1 cliff: 25% of shares vest → FMV of those shares (minus price paid) hits your W-2 as ordinary income
• Years 2–4: Monthly or quarterly vesting continues → each event triggers another ordinary income inclusion
• Tax rate: ordinary income, up to 37% federal + state (California at 13.3%, New York at 10.9%, for example)

For a founder who received 1,000,000 shares at $0.01/share when the company's 409A valuation was $0.10/share, this is inconsequential at the early cliff. But if the stock is worth $4.00/share by the time the 4-year cliff hits and monthly vesting continues, every vest event creates a large ordinary income tax obligation — in cash, even though you may not be able to sell the shares yet.

What an 83(b) election does

An 83(b) election is a written statement filed with the IRS within 30 days of receiving the equity that says: I elect to include the value of this property in income now, not when it vests.

The effects:

• Income recognized at grant: You pay ordinary income tax on (FMV at grant − price paid) × shares. If FMV equals the price paid — common for founders buying shares at the 409A price — the taxable income is zero. Literally a $0 tax bill.
• No tax at vesting: Subsequent vest events create no further income tax. The vesting schedule still governs when you truly own the shares, but there's no tax event at each vest.
• Capital gains treatment on appreciation: Post-election appreciation from grant date to sale is a capital gain — long-term (23.8% federal: 20% + 3.8% NIIT) if you hold the shares more than one year from the election date.²

In the example above: the founder files an 83(b) and pays ordinary income tax on ($0.10 − $0.01) × 1,000,000 = $90,000 at grant. At a 35% marginal rate: $31,500 owed. The subsequent appreciation from $0.10 to the exit price gets long-term capital gains treatment (23.8% federal for HNW sellers in 2026).

What 83(b) elections apply to — and what they don't

Founders' restricted stock and restricted stock awards (RSAs)

This is the most common and most valuable use. When a company is incorporated, co-founders typically purchase shares at a nominal price ($0.001–$0.01/share) and subject them to a vesting schedule. At the time of purchase:

• The 409A FMV is typically at or near the purchase price
• The spread between price paid and FMV is minimal → filing an 83(b) generates near-zero taxable income at grant
• Without an 83(b), future vest events will trigger ordinary income tax on potentially millions of dollars of appreciation

Every founder who receives shares subject to vesting should file an 83(b) election. The cost is near zero at grant; the cost of not filing can be catastrophically high at exit.

Early exercise of ISOs before vesting

Some startup option plans allow early exercise — the holder exercises the option before shares vest. After exercise, the holder owns actual shares subject to a company repurchase right (the vesting schedule continues to govern forfeiture). This creates an 83(b) opportunity:

• File an 83(b) election within 30 days of the early exercise date
• Income recognized at exercise: (FMV at exercise − strike price). If you exercise at the 409A price on or shortly after grant, this spread is near zero
• Start the long-term capital gains holding period clock from the exercise date, not the vest date
• Start the QSBS 5-year clock from the exercise date (see QSBS section below)

Restricted stock units (RSUs) — 83(b) does NOT apply

RSUs are a contractual promise to deliver shares at a future vesting date. Because the holder does not receive actual property until shares are delivered at vest, there is no "transfer of property" for purposes of Section 83 at grant — and therefore no 83(b) election is available.³ RSU taxation is always ordinary income at vest; the planning strategy for RSUs is timing diversification, not 83(b) elections.

Standard (non-early-exercise) options

If your option plan does not allow early exercise and you simply hold unexercised options through vesting, Section 83 applies at exercise (when you receive actual shares). No 83(b) is filed for the option grant itself. ISO or NQSO tax mechanics govern at exercise.

The QSBS connection: starting the 5-year clock early

For founders and early employees at qualifying companies, the interaction between 83(b) elections and Qualified Small Business Stock (§ 1202) is one of the most powerful tax planning combinations available. Under OBBBA (July 2025), § 1202 now excludes up to $15,000,000 of gain from federal taxes for shares held more than 5 years from the acquisition date.⁴

The "acquisition date" is critical:

• Without early exercise: Shares acquired on a vesting schedule have different acquisition dates for each vest tranche. A 4-year vest means most shares can't hit the 5-year QSBS threshold until 9 years from the original grant date.
• With early exercise + 83(b): You acquire all shares on day one. The 5-year QSBS clock starts running from that acquisition date. An employee who early-exercises and files an 83(b) on year one of a 4-year vest has all shares potentially QSBS-qualified 5 years from exercise — one year after the vest schedule completes, not five.

QSBS eligibility requires more than just the 83(b) election — the company must be a domestic C-corporation, the gross assets must have been ≤ $75M at the time of issuance, and the company must be engaged in a qualifying active business. See the QSBS guide for the full eligibility checklist.

How to file: IRS Form 15620

The filing process is straightforward but the deadline is absolute:

1. Use IRS Form 15620. The IRS released Form 15620 in 2025 to standardize 83(b) election filings, replacing the prior letter-format approach. As of 2026, this is the preferred form.⁵ Required information: taxpayer name, address, SSN, description of property, grant/exercise date, FMV at transfer, amount paid, and nature of restriction.
2. File within 30 days by mail. As of early 2026, no electronic submission path exists. Mail to the IRS service center where you file your return, using certified mail with return receipt to create a dated postmark record. Keep the receipt indefinitely.
3. Retain a copy. Keep a signed copy of Form 15620 and the certified mail receipt permanently. You'll need to produce this documentation at a future liquidity event to establish your holding period and basis.
4. Attach to your tax return. Include a copy with your federal income tax return for the year of the grant or early exercise.
5. Notify the company. Many equity plan agreements require you to provide notice to the issuing company; check your grant agreement.

When an 83(b) election is NOT the right move

The election is almost always correct when the spread at grant is near zero. But there are scenarios where more analysis is warranted:

• Large existing spread: If the 409A FMV significantly exceeds your price paid at the time of grant (or exercise), filing 83(b) accelerates a material ordinary income event into the current year. If you expect lower income in future years — or plan to leave before the cliff — accelerating this income may not be optimal.
• Real forfeiture risk: The 83(b) taxes you on property you could forfeit. If you leave before vesting, you don't receive a deduction for taxes paid on forfeited shares — you receive a capital loss limited to the FMV at the election date, which may not fully offset the ordinary income recognized. Assess your actual likelihood of completing the vesting schedule.
• Company with poor prospects: Paying current tax on shares that may never appreciate is a pure cost. At pre-seed stage with a minimal 409A, the risk is usually worth accepting (taxes owed are tiny). At a later-stage grant with a high 409A and substantial spread, evaluate more carefully.
• ISO early exercise with a large spread: If the ISO has already appreciated significantly before you consider early exercise, the AMT preference item at exercise (equal to the spread) can be large. Run the AMT analysis before assuming early exercise is beneficial. See the equity compensation planning guide.

Pre-IPO and post-IPO planning intersections

For employees at companies approaching an IPO, the 83(b) election interacts with several additional decisions:

• Secondary tender offers: If the company offers pre-IPO liquidity through a tender offer, the holding period for long-term capital gains treatment on shares covered by an 83(b) runs from the early exercise date. Shares sold in a tender offer more than 12 months after early exercise qualify for LTCG treatment; less than 12 months generates short-term (ordinary) rates. Check the date math carefully before deciding whether to participate.
• Lock-up period: Post-IPO lock-up (typically 180 days) prevents insiders from selling. Employees who early-exercised and filed 83(b) may already have multi-year LTCG holding periods and potentially satisfied the QSBS clock before the lock-up lifts — a significant advantage over those who exercised at or near IPO.
• RSU cliff at IPO: Many companies grant double-trigger RSUs that vest at IPO. These cannot use 83(b) and generate ordinary income at vest at the public market price. Understanding your equity mix — which grants are early-exercise ISOs eligible for 83(b), which are RSUs that aren't — is essential to pre-IPO planning.
• AMT credit recovery: Even small amounts of AMT paid on early exercises generate Minimum Tax Credit (Form 8801) carryforwards. These are typically fully recovered in the year of a large capital gain event, when regular tax liability greatly exceeds tentative minimum tax.

83(b) election tax savings calculator

Estimate the federal + state income tax impact of filing (or not filing) an 83(b) election. Enter the terms of your equity grant and project your expected FMV at vesting.

1. IRC § 83 — Property Transferred in Connection with Performance of Services (Cornell LII). Default rule: property received subject to a substantial risk of forfeiture (vesting) is taxed when restrictions lapse. Amount included in income: FMV at vest minus amount paid.
2. IRS — 2026 Tax Year Adjustments (Rev. Proc. 2025-32). 2026 LTCG 20% rate threshold (MFJ): $613,700. NIIT 3.8% on MAGI above $250,000 MFJ. Top ordinary income rate 37% above $768,700 MFJ.
3. Treas. Reg. § 1.83-3 — Meaning of Terms (Cornell LII). RSUs do not constitute a "transfer of property" under § 83 until the underlying shares are delivered at vest; no 83(b) election is available for RSUs.
4. IRC § 1202 — Partial Exclusion for Gain from Certain Small Business Stock (Cornell LII). OBBBA (July 2025) raised exclusion cap to $15,000,000 (tiered: 50%/75%/100% at 3/4/5 years). 5-year holding period begins on acquisition date of shares.
5. IRS Form 15620 — Section 83(b) Election. Released 2025, standardizing the prior letter-format election. Required fields: taxpayer name, address, SSN, description of property, date of transfer, FMV at transfer, amount paid, nature of restriction. Filing by certified mail to IRS service center; attach copy to federal return for the year of transfer.
6. IRC § 422 — Incentive Stock Options (Cornell LII). Qualifying disposition: held more than 2 years from grant date and more than 1 year from exercise date. $100,000 per-year limit on ISOs that first become exercisable. Early exercise permitted if plan authorizes; 83(b) election applies to unvested shares held post-exercise.

Tax values reflect 2026 IRS guidance per Rev. Proc. 2025-32 and OBBBA (July 2025). Section 83(b) elections are irrevocable once filed. QSBS eligibility requires meeting company-level and share-level criteria independent of the 83(b) election. Consult a tax attorney or CPA before making any election.