Fidelity NetBenefits 1099-B: Supplemental Stock Plan Basis into TurboTax

Your employer runs its equity comp through Fidelity NetBenefits, you sold vested RSUs or ESPP shares last year, and the 1099-B is reporting a cost basis that looks far too low — often $0. Enter it as printed and TurboTax will tax you on the entire sale as pure gain. That's wrong, and it's a costly mistake. Here's how to report a NetBenefits stock plan sale correctly.

The good news: Fidelity gives you a supplemental document with the right numbers. You just have to know it exists and use it.

NetBenefits Is Not Your Regular Fidelity Brokerage Account

First, a distinction that trips people up: Fidelity NetBenefits is the workplace platform that holds your employer stock plan (RSUs, ESPP, options), and it's separate from a personal Fidelity brokerage account. If you also have a regular Fidelity account, that's a different 1099-B — see the Fidelity 1099-B TurboTax import fix for the standard brokerage case. This article is specifically about the stock plan sales that flow through NetBenefits.

Why the NetBenefits Basis Is Understated

When RSUs vest or you buy ESPP shares, part of the value is compensation income already reported on your W-2. IRS rules prohibit Fidelity from including that compensation income in the basis it reports on the 1099-B. So the reported basis reflects only what you literally paid — typically $0 for RSUs, or the discounted purchase price for ESPP.

Your true basis is higher: the fair market value at vesting for RSUs, or the purchase price plus the taxed discount for ESPP. Report the low number and you pay capital gains tax on income you already paid ordinary tax on. Fidelity provides the corrected figure in a supplemental statement.

Step 1: Download Both Documents

1. Log in to Fidelity NetBenefits
2. Go to the stock plan account, then Documents / Tax Forms
3. Download the 1099-B for the tax year
4. Download the Supplemental Information statement (Fidelity's stock plan cost-basis supplement, sometimes labeled "Supplemental Stock Plan Lot Detail")

The supplement is the document that makes this correct. Grab it every time.

Step 2: Import or Convert the 1099-B

You can import NetBenefits through TurboTax by choosing Fidelity Investments and signing in, then selecting the stock plan account. If the import stalls, mixes up your personal and stock plan accounts, or you'd rather work from the PDF:

1. Upload your NetBenefits 1099-B PDF to a PDF-to-CSV/TXF converter
2. Preview the extracted transactions
3. Download TXF or CSV
4. In TurboTax Desktop: File → Import → From Accounting Software → TXF File

This gets the sales into Form 8949. As with any stock plan account, the converter extracts exactly what's on the 1099-B — including the understated basis — so you still apply the supplement in the next step.

Step 3: Apply the Adjusted Cost Basis

For each stock plan sale:

1. Find the transaction on the Supplemental Information statement
2. Note the adjusted cost basis (it already accounts for the W-2 compensation income)
3. In TurboTax, edit the Form 8949 row and enter the corrected basis, or use adjustment code B with the difference in column (g)

The specifics depend on the award type:

• RSUs: true basis = fair market value at vesting — see RSU cost basis wrong on 1099-B.
• ESPP: basis includes the taxed discount, and qualifying vs disqualifying dispositions change the treatment — see ESPP cost basis double-counted.
• NSO/ISO options: the spread at exercise is usually already on your W-2 — see NSO/ISO stock options double-counted.

Step 4: Sanity-Check the Gain

If you sold shortly after vesting, your gain should be small — only the price movement since vest. A giant gain equal to the full share value is the classic sign the basis wasn't adjusted.

1. Confirm each stock plan row uses the adjusted basis
2. Match total proceeds to the 1099-B summary
3. Verify a near-vest sale shows little or no gain
4. Confirm short-term vs long-term classification

FAQ

Is Fidelity NetBenefits the same as my Fidelity brokerage account?

No. NetBenefits is the workplace platform holding your employer stock plan; a personal Fidelity brokerage account is separate and gets its own 1099-B. This guide covers the NetBenefits stock plan sales specifically.

Why is my NetBenefits 1099-B cost basis $0?

IRS rules bar Fidelity from including the compensation income already on your W-2 in the reported basis. Your true basis is the vesting fair market value (RSUs) or price plus taxed discount (ESPP), which you get from the supplemental statement.

What is the Fidelity Supplemental Information statement?

It's a separate NetBenefits document showing the adjusted cost basis for your stock plan sales — the figure you should report. Download it alongside the 1099-B.

How do I import NetBenefits into TurboTax?

Choose Fidelity Investments in TurboTax's import and select the stock plan account, or convert the 1099-B PDF to TXF/CSV. Either way, apply the supplemental basis afterward.

How do I fix the basis in TurboTax?

Edit the Form 8949 row and enter the adjusted basis from the supplement, or use code B with the difference in column (g). This corrects the understated $0 basis.

Will I overpay tax if I skip the supplement?

Yes — significantly. You'd pay capital gains tax on compensation income already taxed on your W-2. The supplement adjustment prevents that double taxation.

Can I have two Fidelity 1099-Bs?

Yes. If you have both a personal Fidelity brokerage account and a NetBenefits stock plan account, each issues its own 1099-B. They're separate documents with different basis rules — handle each on its own.

Where exactly is the NetBenefits supplement?

In the stock plan account's Documents or Tax Forms area, listed alongside the 1099-B. It's usually labeled "Supplemental Information" or "Supplemental Stock Plan Lot Detail."

What if NetBenefits didn't provide a supplement?

For RSUs, use the fair market value at vesting from your vesting confirmation. For ESPP, use the purchase price plus the discount that was taxed on your W-2. Those give you the adjusted basis to report.

Bottom Line

A Fidelity NetBenefits 1099-B is easy to import and easy to get wrong, because the stock plan cost basis is intentionally understated. Keep NetBenefits separate from your personal Fidelity account, download both the 1099-B and the Supplemental Information statement, import or convert the sales, and apply the adjusted basis on every stock plan row. Your gain should then reflect only the price movement since vesting.

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Sold RSUs or ESPP through Fidelity NetBenefits? Convert your 1099-B free — upload the PDF to get the sales into TurboTax cleanly, then apply your supplement so you're not taxed twice on the same shares.