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Form 8949 walkthrough for RSU sales when 1099-B basis is wrong

Import 1099-B proceeds, enter vest FMV as basis, use the correct adjustment code when the broker did not report basis — then copy to Schedule D.

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You sold RSU shares and your 1099-B shows zero or missing cost basis. You need to know which Form 8949 columns to use, what adjustment code applies, and how vest FMV from your W-2 ties in before Schedule D.

In plain terms

Report each sale on Form 8949 with proceeds from Box 1d and basis equal to from your confirmation (the same amount already taxed as wages). When basis was not reported to the IRS, use the column set for noncovered securities and enter an adjustment code — typically Code B — so tax software does not tax full proceeds as gain. Copy totals to Schedule D. You are not removing the sale; you are fixing basis the broker did not know.

Gather before you start

  • for the sale (all pages).
  • confirmation for that lot with per share and .
  • for the year showing wages in Box 1.

How the tax works

Brokers record the sale execution — proceeds, date, quantity. They often do not receive wage income from payroll, so they report $0 to the IRS even though you already paid income tax on the .

Form 8949 is where you tell the IRS the correct basis before Schedule D summarizes gain. For lots, basis is generally per share on the times shares sold from that lot.

IRS Form 8949 instructions describe adjustment codes when reported basis differs from your correct basis. sales commonly use Code B when basis was not reported to the IRS. Software labels vary but the economic adjustment is proceeds minus correct basis.

Holding period for sold from a lot starts at for typical employee shares. Short-term vs long-term on 8949 follows that date, not .

Multiple lots require a row per lot on Form 8949 if you sell specific lots. FIFO default in software may not match your broker lot if you sold a particular tranche.

What to check on your end

  • Box 1d proceeds vs trade confirm.
  • confirmation × shares sold = basis you enter.
  • Box 1 for year includes that (sanity check).
  • Covered vs noncovered flag on — picks 8949 column.
  • Adjustment amount equals proceeds minus correct basis when broker showed zero.

Deleting the 1099-B import because basis looked wrong

The sale happened — omitting it creates a mismatch with IRS matching programs. Import proceeds and fix basis on Form 8949 instead.

What to pull from your files

  • PDF.
  • confirmation for matching acquisition date.
  • from year.
  • Broker supplemental statement if issued.

Sold 50 shares from a single vest lot

Illustration only, not your tax situation.

Rina sold 50 shares for $8,200 proceeds per . confirmation shows 200 shares vested at $38.00 ($7,600 total on two years ago). Basis for 50 shares is $1,900. Taxable gain is $6,300, not $8,200. Rina completes Form 8949 with adjustment when basis not reported, then Schedule D.

Questions people ask

Code B or Code W for RSU?
Many sales with missing basis use Code B per Form 8949 instructions for basis not reported to IRS. Some software maps to Code W — follow instructions for your situation and software.
Do I re-enter W-2 wages on 8949?
No. already taxed as wages. Form 8949 adjusts the sale basis to avoid double tax on the same dollars.
Sold immediately at vest?
Gain may be small if sale price ≈ . Still report sale with basis near proceeds.
Related tools on this site?
Use the adjustment helper and Form 8949 adjustment codes guide.

When a CPA is worth it

  • Multiple brokers and conflicting for same lot.
  • Sold at a loss but was higher than sale price — wash sale or basis questions.
  • Already filed with zero basis and received CP2000.

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.

Form 8949 basis adjustment for RSU sales when 1099-B cost basis is missing.

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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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