83(b) Election vs AMT: Key Differences Explained

The main difference is that one is a choice and the other is a tax. You decide whether to file an 83(b) election. The AMT applies whenever its calculation comes out higher than your regular tax. The table compares them on what each is, who meets it, the legal and tax treatment, risk, cash needs and a typical case.

When you receive shares that can be taken back until you have worked long enough, they carry a substantial risk of forfeiture. Under Section 83, you are taxed when that risk lapses, on the value then minus what you paid. As a company grows, that value can rise a lot between grant and vesting.

An 83(b) election moves the tax to the day you receive the shares. You send a signed statement to the IRS within 30 days and a copy to your employer. If you paid full value, you report nothing, and the regulations confirm the election still counts. From then on, growth is a capital gain, and your holding period has started.

The election applies to shares, never to options. IRS Publication 5992 calls an election on an option usually void. Once you exercise early and receive unvested shares, those shares can take it. The early exercise guide covers that step.

The AMT is a second way of computing your tax. It adds back some breaks, subtracts a flat exemption and applies rates of 26% and 28%. If the result beats your regular tax, you pay the difference as AMT. The AMT guide walks through the full calculation.

Incentive stock options are the usual trigger. For regular tax, exercising one is not taxed, according to IRS Topic 427. For the AMT, Section 56(b)(3) switches that break off. The spread, the share value minus the strike, becomes AMT income. If you sell the shares in the same calendar year, the adjustment disappears.

For 2026, Rev. Proc. 2025-32 sets the exemption at $90,100 for a single filer and $140,200 for a joint return. It shrinks by 50 cents for each dollar of AMT income above $500,000 single or $1,000,000 joint. AMT paid because of an incentive option can generally be claimed back as a minimum tax credit in later years, under Section 53.

The two rules meet when you exercise incentive options before they vest. The shares you get are unvested, so their AMT income is measured when they vest. The Form 6251 instructions let you choose instead to include it at exercise, by the 30th day after. In practice, this works as an 83(b) election for the AMT.

Example: 20,000 Early-Exercised Options

An early employee exercises 20,000 incentive options at a $1 strike, paying $20,000. The shares are worth $1 that day and vest over four years, 5,000 a year. At each vesting date, they are worth $3, $5, $8 and $12.

With the election, the spread is measured on the exercise date, when it is zero. Without it, $120,000 of AMT income lands over four years, on shares she may not be able to sell. The cost of the election is the $20,000 paid to exercise, which is lost if she leaves before the shares vest.

If she had waited and exercised all 20,000 vested options at $12, no election would apply. The shares would carry no risk of forfeiture. The whole $220,000 spread would be AMT income in that year.

They are not alternatives, so neither is better. The election is a tool, and the AMT is a cost it can reduce. For an employee with incentive options, the useful question is when to exercise. Early, with an election, the AMT income is small, but the cash is at risk. Late, the cash is safer, but the AMT income can be large.

For a founder with restricted stock, the AMT rarely matters, because the incentive option adjustment does not apply. The election there decides regular tax and the start of the holding period. It can also start the clock for the tax break on startup shares, as 83(b) election vs QSBS explains. An outside investor who buys preferred shares for cash meets neither rule.

83(b) Election

For

Fixes income at the lowest value. Starts the holding period early. For early-exercised incentive options, can keep AMT income near zero.

Against

Irrevocable. No refund of tax or exercise cash if you leave early or the company fails. A strict 30-day deadline.

Verdict: the election suits someone who expects to stay and can afford to lose what they paid. The tax at filing is small when the share value is close to what you pay.

Alternative Minimum Tax

For

AMT from incentive options can generally come back as a credit in later years. A same-year sale removes the adjustment.

Against

Taxes paper gains in cash. The credit can take years to recover. Private shares may not be sellable to pay it.

Verdict: the AMT is a timing cost for most option holders. It is manageable when you plan the size and year of each exercise. It hurts when a large exercise meets shares you cannot sell.

If your plan allows early exercise, run the numbers before the 30 days start. Compare the cash to exercise with the AMT you would face later. If you exercise vested incentive options, estimate AMT before year end. Your employer reports each exercise on Form 3921.

The strike on your options comes from a 409A valuation. The gap between that price and later values drives the AMT. For how incentive and non-qualified options differ, see ISO vs NSO. For what changes as shares vest, see vested vs unvested.

Common Mistakes

• Filing an election on optionsThe election applies to shares. An election on an unexercised option is usually void.
• Missing the 30th dayCount from the day the shares are transferred. There is no extension.
• Forgetting the AMT on vested exercisesHolding incentive option shares past December 31 adds the spread to AMT income.
• Ignoring the creditAMT from incentive options can generally be recovered later. Keep Form 6251 and track it each year.

83(b) election

A written statement filed within 30 days that taxes restricted shares at their value when received. Irrevocable without IRS consent.

Alternative minimum tax (AMT)

A second tax calculation with fewer breaks. You pay the AMT if it comes out higher than regular tax.

Substantial risk of forfeiture

A condition, such as staying employed, that must be met before property is fully yours for tax.

Spread

The share value minus the strike price on the day it is measured.

Incentive stock option (ISO)

An employee option that meets Section 422. No regular tax at exercise, but the spread counts for the AMT.

Early exercise

Buying shares under an option before they vest. The shares stay subject to buyback until they vest.

Minimum tax credit

A credit in later years for AMT paid on items such as incentive options. It reduces regular tax down to the AMT level.

Form 6251

The IRS form that computes the AMT. It is attached to your return.

Every rule and figure was checked against the US Code, federal regulations and the IRS on November 6, 2026. Dollar figures are for tax year 2026. The worked example is illustrative arithmetic. State AMT and state income tax are not covered.