For founders and early employees who exercised stock options before vesting (an 'early exercise'), the 83(b) election is the line between substantial tax efficiency and a meaningful tax penalty. If you're navigating liquidity events through a private market marketplace, this filing status becomes a critical gating factor before any secondary sale is considered. If you are still building foundational context around how pre-IPO transactions and employee liquidity work, review the complete guide to pre-IPO investing before evaluating your specific tax position. If you exercised early and want to sell on the secondary, the first question is whether the 83(b) was filed correctly and on time, since option exercise timing also shapes your secondary options. This is educational, not tax advice. If you think you missed an 83(b) or are unsure of your tax position, work with tax counsel before any sale.

This is educational, not tax advice. If you think you missed an 83(b) or are unsure of your tax position, work with tax counsel before any sale.

What 83(b) does

When unvested stock is purchased (early exercise), the IRS default is to tax the difference between fair market value and exercise price at each vesting milestone — meaning you pay ordinary income tax over years as the stock vests and FMV potentially rises. The 83(b) election lets you instead pay tax at the moment of exercise, on the spread between FMV-at-grant and the exercise price (often zero or near-zero for early-stage stock).

If filed correctly, the result is that all subsequent appreciation is treated as long-term capital gain instead of ordinary income — a substantial tax saving for stock that appreciates significantly.

The 30-day window is hard

83(b) elections must be filed with the IRS within 30 days of the original exercise. Postmark counts. There are no extensions, no late filings, no exceptions. Miss the window and the election is permanently invalid for that exercise.

Why this matters at sale

If the 83(b) was filed correctly, your tax basis is the original exercise price plus any tax paid at exercise, and the entire appreciation since then is long-term capital gain (assuming you've held more than a year). If the 83(b) was missed, the analysis is more complicated — portions of your gain may be ordinary income depending on vesting schedule, and the math at sale gets ugly fast.

What to do

  • Pull your 83(b) election letter from your records before any conversation about selling
  • Confirm the IRS receipt — typically a stamped copy returned within 8–12 weeks of filing
  • If you can't find proof of filing, assume the election was missed and run the math both ways before deciding to sell