83(b) Election vs QSBS: Key Differences Explained

An 83(b) election is a choice about when you are taxed. QSBS is a status that decides whether part of your gain is taxed at all. The table compares them on what each is, who uses it, the tax treatment, the risk, when you can get cash and a typical case.

Shares that vest are shares you can lose. If you leave before a vesting date, the company can take back the unvested part. Tax law calls this a substantial risk of forfeiture. By default, Section 83 taxes you as each part vests. You owe tax on its value at vesting minus what you paid, as wages. Your holding period for that part starts then.

The 83(b) election moves that moment to the day you receive the shares. You are taxed once, on the value at transfer minus what you paid. Growth after that is not wages. It becomes a capital gain when you sell. If you paid full value, the taxable amount is zero, so the election costs no tax. Your basis is what you paid plus anything you included in income. Your holding period starts just after the transfer.

How to File

You file a signed written statement, or Form 15620, with the IRS Service Center where you file your return. It must be filed no later than 30 days after the transfer, and the IRS gives no extensions. You also give a copy to the company. The statement names you, the shares, the transfer date, the restrictions, the value and what you paid. Once filed, it can be revoked only with IRS consent.

What It Covers

The election works only on property you already hold. You cannot make it on a stock option. You can make it on shares you buy by exercising an option before it vests, which is called early exercise. Restricted stock units (RSUs) cannot take it either. They are a promise of shares, and Section 83 reaches them only when shares are delivered.

The risk is one-sided. If you leave and forfeit the shares, you get no deduction for the tax you paid. Your loss is only what you paid for the shares minus anything you got back.

QSBS is stock that passes the tests of Section 1202 of the Internal Revenue Code. It must be stock of a domestic C corporation, a company that pays its own income tax. You must get it directly from the company, for money, for property or as pay for work. For stock issued after July 4, 2025, the company’s gross assets must be no more than $75 million before and right after it issues the stock. The company must also run an active business while you hold it.

The exclusion grows with time. For stock acquired after July 4, 2025, you exclude 50% of the gain after three years, 75% after four and 100% after five. Stock acquired on or before that date needs more than five years. The cap per company is the greater of $15 million ($10 million for older stock) and ten times your basis in the shares sold.

There is no application. You claim the exclusion on your return for the year of the sale, and your records have to support it. The QSBS guide sizes the exclusion, and QSBS requirements lists every test.

The link between them is the acquisition date. Section 1202 tests the company on the day you acquire the stock, and it counts your holding period from that day. Without an election, the IRS treats unvested shares as still owned by the company until they vest. So each vesting date generally becomes a new acquisition date for that part of the shares.

That has three effects. First, the asset test is applied at each vesting date. If the company raises a large round in between, later parts can fail the $75 million ceiling. Second, each part starts its own clock, so the last one reaches five years last. Third, a grant made before July 4, 2025 that vests afterward generally falls under the new rules for the later parts.

With a timely election, all the shares are acquired on the day you receive them. The asset test is applied once, often while the company is still small, and one clock starts for every share. The election also sets your basis, which feeds the ten-times-basis part of the cap.

The election does not create QSBS on its own. The company still has to be a C corporation under the ceiling, issue the shares directly to you and run a qualifying business. An election on shares of a company that fails those tests changes only the timing of your tax.

A founder buys 1,000,000 shares for $0.01 each, $10,000 in total, when a Delaware C corporation is formed in 2026. That is their full value. A quarter vests each year. The company holds $1 million at formation, and a large round before the second vesting date takes it past $75 million. The shares are worth $0.40, $1.50, $4 and $8 on the four vesting dates. Six years after formation, the founder sells all of them for $20 each.

With the election, every share is acquired at formation, under the ceiling. The cap is the greater of $15 million and ten times the $10,000 basis, so $15 million of gain is excluded. Without it, only the first quarter vested before the round. The other 750,000 shares were acquired after the company passed $75 million, so their gain is taxed in full.

Without the election, the founder also owes income tax on $3,465,000 of wages before seeing any cash. The fourth vesting year alone adds $1,997,500 of income. The election cost nothing, because the founder paid full value on day one.

The 83(b) Election

For

Turns future growth from wages into a capital gain. Starts the holding period and the QSBS clock at once. Costs no tax when you pay full value.

Against

Tax due now when you pay less than full value, with no cash from a sale. No deduction if you forfeit the shares. A 30-day window with no extension, and no undo.

Verdict: the election suits a holder who pays full value, or close to it, for shares that vest over time. The tax at stake is small then, and the dates it fixes can matter later. When the value at transfer is far above the price, it means paying tax now on shares you may lose.

QSBS

For

Up to $15 million of gain per company, or ten times basis, with no federal income tax. No filing in advance. Works for founders, employees and direct investors alike.

Against

Many tests, all fixed on dates years before the sale. Only stock of a C corporation bought directly from it. A sale before three years gets nothing.

Verdict: QSBS is worth tracking for anyone who holds stock issued directly by a small C corporation. It pays off only for holders who can wait years for a sale. For holders of vesting shares, the 83(b) election is often what keeps the earliest date.

If you are a founder, the decision comes in the first month. Your shares are usually bought for little at formation and vest over several years. Check the 30-day deadline from the date on your stock purchase agreement, and keep a copy of what you sent.

If you are an employee with options, the question arises only if your plan allows early exercise. Exercising early means paying cash for shares you cannot sell yet. Normal exercise after vesting needs no election, and the QSBS clock starts at exercise. The cost basis guide shows how each route sets your basis.

If you invest through a fund or an SPV, a vehicle that pools investors’ money for one deal, neither rule usually decides your result. Shares the vehicle bought from other holders are not QSBS. A company organized as an LLC cannot issue QSBS at all, as LLC vs QSBS explains.

Common Mistakes

• Counting 30 days from the wrong dateThe window starts on the transfer date. A board approval or a later signature does not reset it.
• Filing on an option or an RSUThe election is void for an option and impossible for an RSU. It works on shares you already hold.
• Assuming the election makes shares QSBSIt only fixes the date. The company still has to pass every Section 1202 test on that date.
• Paying less than value without noticingThe gap between value and price is wages in the year of the election. Ask what the shares are worth before you file.
• Losing the paperworkYears later, you need the election and the company’s asset figures to support the exclusion.

83(b) election

A filing within 30 days of receiving unvested property that taxes it at its value that day and starts the holding period then.

Substantial risk of forfeiture

A condition, such as staying employed, under which you can lose property you received. Unvested shares carry it.

Vesting

The point at which shares stop being subject to forfeiture and become fully yours.

Qualified small business stock (QSBS)

Stock of a domestic C corporation, issued directly to the holder while the company was under the gross-asset ceiling. Its gain can be partly or fully excluded from federal tax.

Section 1202

The section of the Internal Revenue Code that defines QSBS and sets the exclusion, the cap and the company tests.

C corporation

A company taxed under subchapter C of the tax code. It pays its own income tax, separately from its shareholders.

Gross assets

A company’s cash plus the tax basis of its other property, tested before and right after it issues stock.

Basis

What you paid for shares plus any amount taxed as income when you got them. Your gain is the sale price minus your basis.

Early exercise

Buying option shares before they vest. The shares are then restricted stock and can take an 83(b) election.

Every rule and figure was checked against the US Code, federal regulations and the IRS on October 29, 2026. They reflect federal law as amended on July 4, 2025. The worked example is illustrative arithmetic on those rules and uses no market data. State tax is not covered.