Few pages of the tax code create millionaires and horror stories as reliably as Section 83(b). Filed in time, a one-page letter can mean the difference between long-term capital gains on a startup windfall and ordinary income on the same dollars. Missed by a day, the opportunity is gone permanently. Here is the whole decision, including the cases where not filing is the smart move.
The default rule the election overrides
When you receive property that can still be forfeited — restricted founder shares, an early-exercised option’s unvested stock — the tax system normally waits. As each tranche vests, its value that day minus what you paid becomes ordinary income. In a company that is succeeding, that is the worst possible schedule: you are taxed at the highest rates on a value that keeps climbing, with a fresh tax event at every vest.
Section 83(b) lets you flip the timing: elect to be taxed once, now, on today’s value. After that, vesting is a non-event for taxes; the capital-gains clock starts immediately; and all future appreciation is capital gain, long-term after a year.
Who can actually use it
- Founders and early employees with restricted stock purchased or granted at incorporation prices.
- Employees who early-exercise options, where the plan permits exercising before vesting — the shares received are restricted stock, electable within 30 days of the exercise.
- Not standard RSUs. An RSU is an unfunded promise; no property changes hands at grant, so there is nothing to elect on. (This is among the most-repeated false hopes in equity forums.)
The math: when filing wins
Founder stock, two timelines
Ana receives 1,000,000 restricted founder shares at $0.0001, paying $100, when FMV equals what she paid. Four-year vesting.
With 83(b) (filed within 30 days): ordinary income today = FMV − price = $0. Years later she sells at $3.00/share: $2,999,900 of gain, all long-term capital gain — potentially eligible for the QSBS exclusion as well, whose holding clock started at the election.
Without 83(b): each vest is taxed at that date’s FMV. If shares are worth $0.50 by the year-two vests and $1.50 by year four, she recognizes hundreds of thousands of ordinary income across the schedule — tax due in cash, on illiquid private shares she may be unable to sell. The same eventual exit now arrives heavily pre-taxed at the worst rates.
The election is most attractive exactly when it is cheapest: spread ≈ 0 (price paid ≈ current FMV) and upside is large. It gets progressively harder to justify as the current spread — and therefore today’s tax bill — grows.
The two ways it goes wrong
- You forfeit. Leave before vesting completes and the unvested shares vanish — but the tax you paid does not come back, and no loss deduction beyond your actual cost is allowed for the forfeited value. Filing is a bet on your own tenure.
- The company dies. Tax paid at a hopeful valuation on shares that end at zero yields, at best, a capital loss limited by the usual rules. Where the election cost real money up front, this stings twice.
Corollary: when the current spread is zero, both risks shrink toward the price you paid — one reason zero-spread early exercise plus 83(b) is the canonical “cheap insurance” version of the move, with the AMT interaction for ISOs covered in the ISO & AMT guide.
The deadline, in bold, again
30 days from the transfer date (grant of restricted stock, or early-exercise date). Postmark rules apply; weekends/holidays roll to the next business day; there are no extensions and the IRS cannot waive a miss. Treat day 10 as your personal deadline. If you are reading this on day 31, the election is gone — plan around the default rule instead.
How to file (the unglamorous part)
- Prepare the election letter — taxpayer info, description and number of shares, transfer date, restrictions, FMV, amount paid, the statement electing under §83(b). Counsel or your cap-table platform usually generates it.
- Sign it. Electronic/digital signatures are now accepted by the IRS for this election.
- Mail to your IRS service center within 30 days — certified mail, return receipt requested. Keep the proof of mailing as if it were the stock itself.
- Copy to the company for its records (and keep your own copy permanently; you may need to show it at sale, years later).
A clean decision frame
- Spread ≈ $0 and you believe in the company → filing is cheap optionality; most informed holders file.
- Spread meaningful, conviction high, cash available, tenure likely → run the numbers with an advisor; often still yes.
- Spread large, tenure uncertain, or paying today’s tax would strain you → the default rule exists for a reason; not filing is a legitimate choice, not a failure.
Whatever you choose, choose it inside the window — with this election, the calendar is the strategy.
Key takeaways
- An 83(b) election tells the IRS: tax me on my restricted shares now, at today's value, instead of at each future vesting date.
- It applies to restricted STOCK and early-exercised options — standard RSUs cannot use it.
- The deadline is 30 days from the grant/exercise date. No extensions, no exceptions, no do-overs.
- Filed early at a tiny valuation, it can convert almost all future growth into long-term capital gains and start the QSBS clock.
- The risks are real: tax paid on shares you may forfeit or that may become worthless is not refunded.
Frequently asked questions
Can I file an 83(b) for my RSUs?
Standard RSUs, no — there is no property transferred at grant to elect on; tax waits for vesting by design. The election belongs to restricted stock awards and to shares from early-exercising options while they are still unvested.
What does filing cost in tax today?
Ordinary income on (fair market value − price paid) at the date of grant/exercise. Founders' stock bought at par value, or options early-exercised at a strike equal to current FMV, often produce a spread of zero — meaning the election can cost nothing today while locking in everything.
What if I file and then leave before vesting?
You forfeit the shares and, painfully, you do not get the tax back, nor a deduction for the forfeited value beyond what you actually paid. That asymmetry is the core risk.
How do I know the IRS received it?
Mail it certified with return receipt, keep a stamped copy if you include a self-addressed envelope, retain proof of mailing forever, and give a copy to the company. The IRS now also accepts electronically signed elections; your counsel or platform (e.g., cap-table software) often generates the filing.
Educational disclaimer: This guide is general information, not financial, investment, tax or legal advice. Figures refer to the tax years stated and change over time; rules differ by jurisdiction and personal circumstances. Verify current figures with the IRS / HMRC and consult a qualified professional before acting. See our full disclaimer.