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1099-B boxes for RSU and stock plan sales: what each field means

1099-B box-by-box guide for equity comp sales — blank or zero basis on RSU sales is common and does not mean your true basis is zero.

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You are reconciling broker forms before tax software import and need to know which 1099-B boxes matter for RSU sales, NSO sales, and ESPP sales when basis is wrong or blank.

In plain terms

reports proceeds and may report and holding period. For equity comp sales, Box 1d is proceeds, Box 1e is (often wrong for ), Box 3 is short- or long-term, and Box 5 may mark noncovered securities. You still reconcile to or exercise from and plan records. Form 8949 carries adjustments when broker basis differs from your records.

Gather before you start

  • PDF from each broker (official tax form, not just year-end summary).
  • Supplemental broker statement with lot detail if provided.
  • or exercise confirmations for each lot sold.
  • for years when shares vested or options were exercised.
  • Prior Form 8949 if you sold lots from older vests.

How the tax works

Brokers must report sales proceeds to the IRS on . Many also report when they know it. Plan shares often arrive with basis the broker never received from payroll, so Box 1e may be blank or zero even when you already paid wage tax at or exercise.

shares typically through employer payroll. reports wage income at . The brokerage account may not get transmitted as . shares after exercise should have basis near exercise because spread was wages, but brokers sometimes use strike price or zero if exercise data was missing.

Covered vs noncovered securities (Box 5 and related indicators) change which Form 8949 column you use. sales are often noncovered, meaning the broker had weaker basis reporting obligations. Box 1a description and CUSIP help match each sale to a lot when multiple vests sold in one year appear as separate lines or one aggregate line.

Date sold appears in Box 1c. Holding period in Box 3 references broker records, which may use trade date not . For , holding period for tax often starts at . Importing into tax software before correcting basis creates inflated — fix the story on Form 8949, not by deleting the .

sales combine discount wages on the with post-purchase . alone rarely tells the full wage piece. Transferring shares between brokers may also drop on the new firm's , so carry and exercise records when you move accounts.

What to check on your end

  • Box 1d proceeds vs trade confirmation.
  • Box 1e basis vs × shares () or exercise ().
  • Box 3 holding period vs your or exercise date records.
  • Box 5 or covered/noncovered indicator for Form 8949 column choice.
  • Multiple lots: supplemental statement vs summary line.
  • Fees: whether proceeds are net or gross of commissions.
  • Corrected after broker amendment.

Treating blank Box 1e as zero basis

Blank often means unknown, not zero economic basis. For , basis usually equals wage income already on your . Enter that basis on Form 8949 with the adjustment code the instructions describe for the year you file.

What to pull from your files

  • all pages including supplemental.
  • confirmations with and share count per lot.
  • wage detail for or option income.
  • Form 8949 draft from tax software.
  • Broker adjustment worksheet if offered.
  • Schedule D summary totals.

Noncovered RSU lot with zero basis on 1099-B

Illustration only, not your tax situation.

Alex receives showing Box 1d proceeds $8,000, Box 1e blank, Box 5 indicating noncovered security, Box 3 short-term. Alex's confirmation shows 100 shares at $75 ($7,500 on two years ago). Alex reports $8,000 proceeds and $7,500 basis on Form 8949 with the adjustment method for basis not reported to the IRS. is about $500, not $8,000.

Questions people ask

Which 1099-B box is cost basis for RSU sales?
Box 1e. It may be blank or zero for lots even when your true basis is . Use plan records, not the empty box alone.
What does noncovered security mean on 1099-B?
Generally that the broker was not required to report basis to the IRS for that sale. You still must report correct basis on your return. Form 8949 instructions describe which column to use.
1099-B vs supplemental statement?
The official goes to the IRS. Supplemental PDFs often show lot-level dates and . Use supplemental detail to build Form 8949 when the summary line aggregates lots.
Do I report 1099-B if I already paid tax at RSU vest?
Yes. The sale is still reported. tax was wages; the sale reports gain or loss after basis. You are not taxed twice on the same dollars when basis is correct.
Short-term vs long-term on 1099-B for RSUs?
Holding period usually runs from for shares received from . If Box 3 disagrees with your records, use and Form 8949 instructions.

When a CPA is worth it

  • Dozens of lots on one summary line.
  • Wash sales across sales and open market purchases.
  • Broker basis partially populated but wrong for some lots only.
  • International brokerage forms instead of US .

Sources and notes

Primary tax claims on this page are supported by the official and secondary sources below. Broker and software links describe reporting mechanics — confirm rules against IRS or state guidance.

1099-B box definitions for equity-comp sales and Form 8949 adjustments.

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VestingTax.com is not a CPA firm or tax preparer. Grants, employers, and states all differ. Use the cited IRS and state sources above, your own documents, and a qualified tax professional before you make decisions from this guide.

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