You know your 1099-B basis is wrong and tax software is computing a huge gain. This page is a filing-season walkthrough for adjusting RSU sales to vest FMV without deleting forms or double-counting W-2 income.
In plain terms
Gather before you start
- for each sale.
- per share for the lots sold.
- showing wages in the year.
- Tax software account or paper Form 8949 instructions open.
Software labels change by year. Follow your product's RSU or basis adjustment workflow and keep vest proof.
How the tax works
Brokers file with incomplete basis while the IRS also receives your wages.
You are responsible for reporting the correct gain even when forms disagree.
Form 8949 adjustment codes explain why your basis differs from the broker statement.
Without adjustment, you risk overpaying tax on income already taxed at .
What to check on your end
- × shares sold equals proposed basis.
- includes wages in the correct tax year.
- Proceeds on 8949 match after fees if applicable.
- Holding period (short vs. long term) measured from .
- Software adjustment code matches IRS instructions for incorrect broker basis.
Adjusting to a round number without records
What to pull from your files
- imported into software (note original $0 basis).
- Form 8949 adjustment column after you enter .
- Box 1 supporting wage amount.
- confirmation PDF archived by grant and date.
- Schedule D total gain reasonable vs. price change since .
Example scenario (hypothetical)
Illustration only, not your tax situation.
Questions people ask
- Which Form 8949 box do RSU sales use?
- Many plan sales are noncovered and short-term, but check Box 3 on your for holding period and Box 5 for covered/noncovered status. Your software usually routes the sale once you import the form.
- Do I enter an adjustment code?
- IRS instructions for Form 8949 describe codes when basis reported to the IRS is incorrect. Tax software often prompts for this when you change basis from the imported amount.
- What if I already filed with $0 basis?
- You may need to amend the return for that year. Gather records before amending so the corrected gain matches basis.
- Can I skip Form 8949 if gain is small after adjustment?
- Reporting rules depend on totals and software eligibility for summaries. Even small gains usually still require reporting the sale with correct basis.
When a CPA is worth it
- Multiple vests sold on one aggregated line.
- Employer issued a corrected after you filed.
- You transferred shares between brokers.
- You are amending a prior-year return.
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 adjustments; TurboTax link is filing workflow only, not tax law.
- Instructions for Form 8949 — Sales and Other Dispositions of Capital Assets
Internal Revenue Service · Official
How to report sales when broker-reported basis is incorrect, including adjustment codes.
- Filing taxes for restricted stock, RSUs, or performance awards (tax guide PDF)
Fidelity Stock Plan Services · Brokerage explainer
Explains W-2 vest income, 1099-B with $0 basis, supplemental adjusted cost basis, and Form 8949 reporting.
- TurboTax community — RSU cost basis adjustment on 1099-B
Intuit TurboTax (community forum) · Community forum
Filing workflow only: marking basis incorrect/missing and entering vest FMV as adjusted basis, not a substitute for IRS rules.
Community and tax-software links describe filing steps, not tax law. Confirm rules against official sources or your advisor.
Related calculators
Related pages
- Why Is My RSU Cost Basis Zero?
Zero basis on 1099-B usually means the broker did not link your vest wage income — not that tax was skipped.
- RSU Taxes in TurboTax
TurboTax can handle RSUs when you import forms in the right order and fix basis before filing.
- RSU Sale Reported Twice: What To Check
Double-counting usually means basis was not adjusted — fix basis before panicking about tax owed.
For learning, not filing
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.
