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🇺🇸 US · US tax

Form 3921

Also called: IRS Form 3921

In one line

The IRS form a company issues when you exercise ISOs, reporting the details needed to calculate AMT.

In plain English

After you exercise ISOs, the company sends Form 3921 with the dates, strike price and fair market value. Your tax preparer uses it to work out any AMT and your cost basis.

If you were explaining it to a 5-year-old

It's the receipt the shop gives you after you use a special voucher, so the taxman can check the numbers.

Why it matters when you sell

Form 3921 is the paper trail behind your AMT and future gain, so keeping it matters when you later sell and report the shares.

Related terms

Incentive stock option (ISO)Alternative minimum tax (AMT)Bargain elementForm 6251

Put it to use

Cost to exercise + AMT

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Sources

Primary references for this term: IRS (US tax). Our definitions are written in plain English and kept evergreen — see the glossary methodology. General information, not advice.

Educational information only — not financial, tax or legal advice, and not an offer to buy or sell any security. Definitions are general; your own documents and local law govern your situation. PrivateTechShares is independent and not a broker or marketplace.