The 83(b) election deadline is 30 calendar days from the date your restricted stock is issued, and there is no extension for any reason. File within that window and you lock in today's low valuation for tax purposes. Miss it, and every future vesting event becomes a taxable event at ordinary income rates, on stock you may not be able to sell. For a founder who takes restricted stock at incorporation, this single filing decides whether years of company growth get taxed as capital gains or as ordinary income, a difference that can run into six figures. The IRS finally made this easier to get right in 2025 with an electronic filing option, but the clock itself has not changed, and a recent postmark rule change makes the paper route riskier than before.
What an 83(b) election actually does
An 83(b) election tells the IRS to tax you now, on the stock's current value, instead of later as each tranche vests. For a founder receiving stock at $0.0001 a share, that upfront tax bill is close to zero.
Without the election, the default rule under Section 83 kicks in: you owe ordinary income tax every time a chunk of your restricted stock vests, based on whatever the stock is worth on that date, not what you paid for it. If your company's value climbs while your shares vest over four years, you are taxed at your highest marginal rate on paper gains you have not touched.
File the election, and that entire appreciation shifts from ordinary income to capital gains when you eventually sell. It also starts your QSBS five-year holding clock at grant instead of at vesting, which matters if you are hoping to exclude gains under Section 1202 later.
The cost math: filing versus not filing
Filing an 83(b) election on a typical founder grant costs $0 in tax today. Skipping it can cost hundreds of thousands of dollars later, and the math is not close.
Take a founder issued 1,000,000 shares at incorporation, FMV $0.0001 per share, vesting over four years. Filed on time, the taxable income at grant is $100, effectively nothing.
Now run the no-election version. Say the company's common stock is worth $2.00 a share by the time the last tranche vests. Each vesting date is a separate taxable event at ordinary income rates on the spread between what was paid and that date's FMV. Across the full grant, that is roughly $2,000,000 of ordinary income recognized over four years, taxed at a combined federal and state rate that can reach 45 to 50 percent in high-tax states. That is a $900,000-plus tax bill on stock the founder cannot sell to cover it.
This is not a hypothetical edge case. It is the standard outcome for any founder who skips the election and the company succeeds. The math gets worse, not better, the faster the company grows.
The mistake that causes founders to miss the 83(b) election deadline
Most missed 83(b) elections are not a decision, they are a timing accident. The 30-day clock starts on the date the stock is transferred, which is usually the board approval and issuance date, not the day a founder signs paperwork or receives a countersigned copy from counsel.
If your board approves the grant on day zero but your attorney sends the documents on day 14, you have already burned almost half your window before you have even seen the paperwork. Confirm the actual issuance date directly, do not assume it matches the date on your inbox.
A second, newer trap: a USPS rule change effective December 24, 2025 means mail is now postmarked when it is processed at a facility, not when it is dropped in a collection box. Dropping a paper election in a mailbox on day 29 no longer guarantees a day-29 postmark, and a late postmark invalidates the election entirely. The safer move in 2026 is to file electronically through the IRS Form 15620 e-filing portal, live since July 2025, which gives an instant, timestamped confirmation instead of relying on the mail.
How to file the 83(b) election correctly
Filing correctly means confirming the exact grant date, gathering FMV documentation, and submitting through Form 15620 well before day 30, not on it.
- Confirm the transfer date with company counsel the same week you receive the grant, not the week you get around to reading the paperwork.
- Gather the required details: your SSN, the company's EIN, share count, fair market value per share at grant, and the vesting schedule.
- File Form 15620 electronically through the IRS's e-filing portal if you have an ID.me account set up, since this gives instant confirmation instead of a mail receipt.
- If filing on paper, send it certified mail with return receipt requested from a staffed USPS counter, never a drop box, and do this by day 20 to build in a buffer.
- Send a copy of the filed election to your company's finance or legal contact. This is a separate requirement from filing with the IRS, and skipping it creates recordkeeping problems later.
- Save the confirmation number or certified mail receipt with your tax records for at least seven years.
When it might not be the right call
Filing is not automatic just because it is usually correct. Skip it when the upfront tax bill is real money you cannot afford, or when you expect to leave before your stock fully vests.
If you are joining a later-stage company at a meaningful fair market value, an 83(b) election means paying real tax now on stock that might be worth less, or nothing, if you leave early or the company stalls. You do not get that tax back if the shares are forfeited.
The founder case is different. At incorporation, the FMV is close to zero, the tax cost of filing is close to zero, and the downside of not filing is capped only by how well the company does. For a founder receiving stock at inception, skipping the election is almost always the wrong call.
The move to make this week
If you or your co-founder received restricted stock in the last 30 days and have not filed, stop reading and confirm the exact grant date today. Everything else on this list only matters if you are still inside the window.
If the window has already closed, do not spend time searching for a workaround. There is no cure for a missed 83(b) deadline. Talk to a tax advisor about damage control on the specific tranche instead of chasing an exception that does not exist.
Frequently asked questions
What is the deadline to file an 83(b) election?
30 calendar days from the date the restricted stock is transferred to you, usually the board approval and issuance date. There are no extensions, and weekends and holidays count toward the 30 days.
What happens if I miss my 83(b) election deadline?
You lose the option permanently for that grant. Every future vesting tranche is taxed as ordinary income on the spread at vesting, instead of at the low grant-date value.
Can I file an 83(b) election electronically?
Yes. The IRS opened an e-filing portal for Form 15620 in July 2025. It requires an ID.me account and gives an instant, timestamped confirmation, unlike mailed paper filings.
Does an 83(b) election affect my QSBS eligibility?
Yes. Filing starts your five-year QSBS holding period at the grant date instead of at each vesting date, which can be the difference between qualifying and not qualifying for the Section 1202 exclusion.
Do RSUs need an 83(b) election?
No. Restricted stock units are a promise of future shares, not property transferred today, so there is nothing to elect on. Filing one for RSUs has no legal effect.
Should every founder file an 83(b) election?
Almost always yes at incorporation, when FMV is near zero. It becomes a real decision only for later hires receiving restricted stock at a meaningful valuation, where the upfront tax bill is real money at risk.
Founders lose more money to a missed 30-day deadline than to almost any single tax decision they will make. Set the reminder the day the stock is issued, not the day someone reminds you it exists.