How to Read Your 1099-B: Every Box Explained

Your broker's 1099-B is dense — columns of numbers, box letters, "covered" and "noncovered" labels, and a wash sale column that seems designed to confuse. But it's really just reporting a few facts about each thing you sold. Here's every box on a 1099-B explained in plain English, so you know exactly what you're looking at and what to do with it.

Once you can read a 1099-B, the rest of capital-gains filing is mostly copying the right numbers to the right place.

What a 1099-B Is For

A 1099-B reports sales of securities — stocks, ETFs, mutual funds, bonds, options — from your brokerage account for the year. Your broker sends a copy to you and to the IRS. Its job is to give you (and the IRS) the numbers you need to figure your capital gains and losses on Form 8949 and Schedule D.

It reports sales, not dividends or interest — those live on the 1099-DIV and 1099-INT, which often come bundled with the 1099-B in a "Consolidated 1099."

The Core Boxes for Each Transaction

For every security you sold, the 1099-B reports these fields:

• Description of property (Box 1a): what you sold — for example, "100 sh AAPL."
• Date acquired (Box 1b): when you bought it. May say "Various" if the shares came from multiple purchase dates.
• Date sold or disposed (Box 1c): when the sale happened.
• Proceeds (Box 1d): what you received from the sale (sometimes net of fees).
• Cost or other basis (Box 1e): what you originally paid. This may be blank for noncovered securities.
• Accrued market discount (Box 1f) and Wash sale loss disallowed (Box 1g): adjustments — 1g is the common one, showing a disallowed loss from a wash sale.
• Gain or loss: some brokers compute it; it's proceeds minus basis, plus/minus adjustments.

The two numbers that drive your tax are proceeds (1d) and cost basis (1e). The gap between them, adjusted for wash sales, is your gain or loss.

Covered vs Noncovered — and the Box Letters

This is the part that trips people up. Each transaction is sorted into a category that tells you two things: the holding period (short-term vs long-term) and whether the broker reported cost basis to the IRS (covered vs noncovered).

Box	Holding period	Basis reported to IRS?
A	Short-term	Yes (covered)
B	Short-term	No (noncovered)
D	Long-term	Yes (covered)
E	Long-term	No (noncovered)
C / F	Short / Long-term	Not reported on a 1099-B

Covered securities (Boxes A and D) have basis reported — the easy case. Noncovered securities (Boxes B and E) often have blank cost basis, because the broker isn't required to report it, usually on shares bought before basis-reporting rules took effect. You fill that basis in yourself — see noncovered securities with missing cost basis and cost basis reporting rules.

Each box maps to a section of Form 8949. For a deeper look at the short-term boxes, see Form 8949 Box A vs B vs C; for long-term, Box D vs E vs F.

Other Boxes You Might See

• Federal income tax withheld (Box 4): backup withholding, if any was taken. This counts as tax already paid — don't forget it.
• Wash sale loss disallowed (Box 1g): the disallowed loss amount; it must carry to Form 8949 with code W — see wash sales explained.
• Noncovered checkbox / "basis not reported": the flag telling you basis is your responsibility.
• State information: for state tax reporting, where applicable.

Reading the Summary Page

Most 1099-Bs end with a summary grouping totals by box (short-term covered, long-term noncovered, etc.). This page is your reconciliation tool: the total proceeds there should match the sum of your Form 8949 rows. Always tie your entries back to this summary before filing.

From Reading It to Filing It

Once you can read your 1099-B, getting it onto your return is mechanical: each transaction becomes a Form 8949 row in the matching box, and the boxes total onto Schedule D. For a full 1099-B, converting the PDF fills those rows for you — see how to import a 1099-B into TurboTax and, for big documents, 1099-B with too many transactions.

FAQ

What is the most important number on a 1099-B?

Proceeds (Box 1d) and cost basis (Box 1e). The difference between them, adjusted for any wash sale in Box 1g, is your capital gain or loss — the number that actually affects your taxes.

What does covered vs noncovered mean on a 1099-B?

Covered means the broker reported your cost basis to the IRS (Boxes A and D). Noncovered means it didn't (Boxes B and E), usually on older shares — you supply the basis yourself.

Why is the cost basis blank on my 1099-B?

The blank rows are noncovered securities the broker isn't required to report basis for, typically bought before basis-reporting rules applied. You reconstruct and enter the basis from your own records.

What does Box 1g (wash sale loss disallowed) mean?

It's the amount of a loss disallowed because you rebought a substantially identical security within 30 days. That amount carries to Form 8949 with code W and can't be deducted this year.

Does a 1099-B include my dividends?

No. The 1099-B reports securities sales only. Dividends are on the 1099-DIV and interest on the 1099-INT, though all three often arrive bundled in a Consolidated 1099.

How do I use the boxes to fill out Form 8949?

Put each transaction in the Form 8949 section matching its box (A, B, D, or E), copy proceeds and basis, add any wash sale code and adjustment, and let the totals flow to Schedule D.

What is Box 1a on a 1099-B?

Box 1a is the description of the property sold — the security name and share count, such as "100 sh AAPL." It identifies what each sale line refers to.

Does every broker's 1099-B look the same?

The IRS boxes are standardized, but brokers format the layout differently — some group by box, others by account. The same core fields (proceeds, basis, dates, wash sale) appear on all of them.

What if I received 1099-Bs from two brokers?

Report each one separately, mapping its transactions to the matching Form 8949 boxes and reconciling each to its own summary. Keeping them separate makes any discrepancy easy to trace to the right broker.

Bottom Line

A 1099-B is just reporting what you sold, when, for how much, and what it cost — plus a category (the box) that sets the holding period and whether basis was reported. Focus on proceeds and cost basis, watch for blank basis on noncovered rows and wash sales in Box 1g, and reconcile everything to the summary page. Read it once with this map and it stops being intimidating.

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Ready to turn your 1099-B into a filed return? Convert it free — upload the PDF and get every box mapped into a clean, TurboTax-ready Form 8949 without decoding columns by hand.