The 83(b) election: the 30-day window that decides your startup tax bill

If you're a founder or early employee receiving restricted stock — shares subject to vesting — you face one of the few genuinely irreversible deadlines in the tax code. By default, you're taxed as each tranche vests, at ordinary income rates, on whatever the shares are worth then. An 83(b) election flips that: you elect to be taxed now, on the grant-date value of all the shares, and everything after is capital gain. When the shares are nearly worthless at grant — the standard founder situation — the election costs almost nothing and can save enormous sums. The window is 30 days from the grant. Not 31.

Default taxation vs. the election

• Default (no election): each vesting date is a taxable event. You owe ordinary income tax on (fair market value at vesting minus what you paid). If the company is taking off, every vest is a bigger bill — on shares you usually can't sell to pay it.
• With 83(b): you're taxed once, at grant, on (fair market value at grant minus what you paid). Founders who buy their stock at fair value at incorporation report zero income. The capital gains holding period starts immediately.
• All future appreciation becomes capital gain, taxed only when you actually sell — at long-term rates if held over a year, and possibly 0% under QSBS rules if the stock qualifies.
• The election applies to restricted STOCK (including early-exercised options), not to standard unexercised options or RSUs — RSUs cannot take an 83(b).

When 83(b) is the right call — and when it isn't

1. Clear yes: founder stock at incorporation, bought at fair market value. The taxable spread is zero, so the election is free insurance. This is close to universal practice.
2. Usually yes: early-exercising options when the strike price still equals current fair value — again a zero-spread election that starts your capital gains and QSBS clocks.
3. Think harder: joining a later-stage company where the current value is well above your price. The election means writing a real tax check today on paper value — money you lose entirely if the company fails.
4. Usually no: when the tax due at election is large relative to your liquid savings, or the company's prospects are genuinely coin-flip and the spread is big. Paying six figures of tax for shares that later zero out is the nightmare case — you get no refund, only a capital loss limited to $3,000/year against ordinary income.
5. Never possible: RSUs, or options you haven't exercised. If someone tells you to '83(b) your RSUs,' find a new advisor.

The forfeiture asymmetry — read this twice

Here's the trap inside the trap: if you file an 83(b), pay tax, and then leave (or are fired) before vesting, you forfeit the unvested shares AND you get no deduction or refund for the tax you paid on them. The IRS treats it as if the taxed income never becomes reclaimable. This is why the calculus is easy when the election costs $0 (nothing to lose) and gets genuinely hard when it costs real money: you're betting the tax paid against both the company's success and your own tenure.

Filing it right

• The election is a short statement (the IRS provides a model form) with your info, the share count, grant date, amounts paid, and fair market value.
• File within 30 calendar days of the stock transfer — weekends and holidays count.
• Send certified mail with return receipt to your IRS service center (or file electronically), and keep proof forever — you'll need it at exit, possibly a decade later.
• Give a copy to the company for its records, and report consistently on that year's return.
• Don't guess on valuation: use the price from the board-approved grant or a current 409A valuation.

Default vs. election, compressed

If the table looks lopsided, that's because it is — for zero-spread grants, filing is close to strictly better. The comparison only becomes a real decision when the grant-date spread (and therefore the tax due at election) is a number that would hurt to lose.

The bottom line

The 83(b) election is a bet that's nearly free and hugely asymmetric when your stock's grant-date spread is zero — which is precisely the founder and early-exercise situation it was made for. File it in week one, certified, copies everywhere. When the spread is large, it stops being free insurance and becomes a real wager of today's tax dollars on the company's future and your own tenure — size it like one. Either way, decide inside the 30 days, because the code offers no second chances on this one.