Got Startup Stock? Don't Miss the 83(b) Deadline

Short answer: If you receive eligible unvested startup shares, an 83(b) election may let you pay tax based on today's value rather than a higher value as the shares vest. But you generally have only 30 days after the shares are transferred to file it.

That deadline can arrive long before your first vesting date. Waiting until tax season may mean the choice is already gone.

The right question is not just “Can I file?” It is “Does paying tax now make sense for these shares—and for me?”

1. Does Your Stock Qualify?

An 83(b) election may apply to shares you receive for your work but could still lose before they vest. Vesting means earning the right to keep them. You need shares you already own, not just a promise or option to receive them later.

• Restricted stock: You receive shares now, but may lose them if you leave before vesting. This is a common situation to review for 83(b).
• RSUs: A grant usually promises shares in the future. An ordinary RSU grant generally does not qualify.
• Stock options: An option grant generally does not let you file an 83(b) election for the shares.
• Early-exercised options: If your company lets you exercise before vesting and you receive unvested shares, you may be able to file an election then.

Do not rely on the word “stock” in your offer letter. Check the award agreement, whether shares have actually been transferred, and what happens if you leave.

If you exercise ISOs before vesting, an 83(b) election can affect alternative minimum tax, or AMT. It does not change the regular income tax on that exercise. The example below is for restricted stock, not ISOs. See our guide to ISOs in an acquisition.

2. What Could the Tax Savings Be?

Without an election, eligible restricted stock is generally taxed like pay when it vests. The taxable amount is its value then minus what you paid. With a valid election, you use the value when you received the shares instead. The IRS explanation of this choice notes that later growth generally is not taxed as pay at vesting.

Suppose you buy 100,000 unvested shares for $1,000, and they are worth $1,000 when transferred:

• With a timely election: The amount taxed as pay is $0, because the value equals what you paid.
• Without an election: If all the shares later vest when they are worth $200,000, $199,000 would generally be taxed like pay.

That is $199,000 less income taxed as pay when the shares vest, not a $199,000 tax saving. Your actual savings depend on tax rates and when you sell.

With an election, later growth may instead be taxed as capital gain when you sell, as the IRS examples of electing on unvested shares show. How long you hold the shares still matters; the sale is not automatically tax-free.

For the broader exercise-and-sale picture, see our equity compensation planning guide.

3. When Does the 30-Day Clock Start?

Generally, it starts when the shares are transferred to you—not when they vest, when you can sell them, or when a payroll form arrives.

For example, if eligible shares are transferred on September 1, 2026, the ordinary deadline is October 1, 2026. A September 2027 vesting date does not give you another year to decide.

The IRS deadline instructions allow the next non-holiday weekday when day 30 falls on a Saturday, Sunday, or legal holiday. An ordinary tax-return extension does not extend this separate deadline.

Confirm the transfer date from the documents rather than guessing from a stock-portal notification. If the clock is already running, get advice promptly.

4. What If You Leave—or the Stock Falls?

You may owe tax before you can sell the shares. That is the trade-off.

Suppose you pay $10,000 for shares worth $100,000 and elect to have the $90,000 difference taxed as pay. You later leave before vesting, and the company buys back all the unvested shares for your original $10,000.

You get your $10,000 back, but the tax on the $90,000 is not automatically refunded. Because you recovered everything you paid, there is also no loss to deduct from giving up the shares in this example.

If the stock falls in value, you usually cannot undo the election.

Before electing, consider the tax due now, your ability to pay it without selling shares, your likelihood of staying through vesting, and whether you can afford the investment to fail. A promising company is not a guaranteed payout.

5. How Do You File—and Prove It?

Use the IRS election form and filing instructions for Form 15620. You can also use a signed written statement containing all the required information.

You can submit Form 15620 online with the IRS using an IRS Online Account. You can also mail a signed election to the IRS office where you file your federal return; check the current address in the instructions.

Give a copy to the company or person you worked for. If someone else received the shares for your work, give them a copy too.

Keep the election, stock agreements, and records supporting the shares' value. Save the IRS submission confirmation or proof of timely mailing and delivery. USPS certified or registered mail can help document a paper filing. Clicking “submit” in your company's stock portal is not proof of filing with the IRS.

How LightUp Tax Helps With Startup Equity

A low stock value can make an 83(b) election attractive, but filing a form is only one part of the decision. LightUp Tax compares electing with waiting, models the tax and cash needed, and explains what changes if you leave, the shares fall, or an exit takes longer than expected.

We also look beyond this election. Your prior returns, household income, investments, business interests, and future plans help us identify suitable tax-saving opportunities—from exercise and sale timing to more advanced strategies when the facts support them. Recommendations are built around your numbers, cash needs, and risk tolerance, not a standard checklist. Our high-income tax planning guide explains that broader approach.

Comprehensive Tax Planning Consulting generally ranges from $2,500 to $3,500. If we do not identify potential tax-saving opportunities worth at least three times the consultation fee, we refund that fee under our 3× Tax Savings Opportunity Guarantee. Implementation is quoted separately; the planning fee can be credited toward that work.

If you are receiving startup shares or considering an early exercise, tell us about your situation. Include the transfer date or upcoming exercise date so our team can assess the next step. If a deadline is close, contact your adviser directly as well—submitting an intake does not file an election or extend the deadline.

Frequently Asked Questions

Can I file an 83(b) election for RSUs?

Generally not for an ordinary RSU grant. It is usually a promise of future shares, not a transfer of unvested stock.

Can an election be useful if no tax is due now?

Yes. If the shares' value equals what you paid, there may be no income to tax at that point. Filing on time can still change how later growth is taxed.

Can I fix a missed deadline with my tax return?

Usually not. Filing the election with a later return or paying a penalty does not generally cure a missed 30-day deadline. Have an adviser check the dates and facts promptly.

Related LightUp Tax Guides

• Company Was Acquired? What Happens to Your ISOs?
• The $6.6 Billion Wake-Up Call: Is Your Equity Strategy Ready for a Liquidity Event?
• High-Income W-2 Tax Planning in 2026: 7 Moves to Review Before Year-End
• Sold Company Stock? Watch Out for Estimated Tax

Official Sources

• IRS explanation of restricted-stock elections and forfeiture
• IRS election form, deadline, and mailing instructions
• IRS online election form
• IRS explanation of early-exercised ISOs and AMT
• IRS examples of electing on unvested shares
• Stock-transfer rules
• Limits on revoking an election