Form 8949 From 1099-B: Everything You Need to Know
Tax season means reconciling broker statements with IRS forms that seem designed to confuse. Your broker sends a 1099-B summarizing every sale you made. The IRS wants that same information on Form 8949, in a specific format, broken into short-term and long-term buckets. Once you understand the mapping between the two, the process becomes much more manageable.
What Is Form 8949?
Form 8949 is the IRS form for reporting sales and other dispositions of capital assets. If you sold stocks, bonds, mutual funds, ETFs, options, cryptocurrency, or real estate during the tax year, those transactions belong on Form 8949 1099-B before they flow anywhere else.
Think of it as the transaction-level detail sheet. The IRS wants to see every individual sale — what you sold, when you bought it, when you sold it, what you received, what you paid, and whether any adjustments apply.
The form acts as the bridge between your 1099-B (what your broker reports) and Schedule D (where your capital gains and losses are summarized). You cannot skip Form 8949 and go straight to Schedule D. Every transaction lives on 8949 first.
What Goes on Form 8949
The form has eight columns, labeled (a) through (h). Each maps to data your broker already collected.
Column (a): Description of property. The name or description of what you sold — typically the stock ticker or fund name, plus share count. For example: "100 sh AAPL" or "50 sh VTSAX."
Column (b): Date acquired. The date you originally purchased the asset. This determines whether a sale is short-term (held one year or less) or long-term (held more than one year).
Column (c): Date sold or disposed. The date the transaction settled or closed. This is typically the trade date.
Column (d): Proceeds. The gross amount you received from the sale, before commissions or fees.
Column (e): Cost or other basis. What you originally paid for the asset, including any commissions paid at purchase. This is the number your broker may or may not report to the IRS.
Column (f): Adjustment code. A letter code signaling why the reported numbers need modification. Most common: W for wash sales. Other codes: B (basis not reported to IRS), H (long-term gains on collectibles). Many transactions have no code.
Column (g): Adjustment amount. The dollar amount of the adjustment in Column (f). For a wash sale, this is the disallowed loss entered as a positive number.
Column (h): Gain or loss. The final calculated result: proceeds minus cost basis, plus or minus any adjustment. This flows to Schedule D.
How 1099-B Data Maps to Form 8949
The 1099-B is essentially a pre-filled version of the Form 8949 1099-B data. The mapping is almost one-to-one:
| 1099-B Field | Form 8949 Column |
|---|---|
| Description / security name | Column (a) |
| Date acquired | Column (b) |
| Date of sale | Column (c) |
| Proceeds | Column (d) |
| Cost or adjusted basis | Column (e) |
| Wash sale loss disallowed | Column (g) with code W in (f) |
| Net gain or loss | Column (h) |
The main addition Form 8949 makes is the adjustment code in Column (f). Your 1099-B may note "wash sale" in plain language; the form wants the letter W.
Form 8949 also requires proper separation by box type — which transactions go on Part I (short-term) vs Part II (long-term), and which checkboxes apply.
Covered vs. Noncovered Securities
Transactions on your 1099-B are grouped under different boxes. Boxes A and D are covered securities — your broker is required to report the cost basis to the IRS. Boxes B and E are noncovered securities — the broker reports proceeds but not cost basis.
This changes which checkbox you mark on Form 8949. Part I has three checkboxes: A (covered short-term), B (noncovered short-term), C (other short-term). Part II mirrors for long-term: D, E, F.
Practically, covered means the IRS already knows your basis number. If you enter a different basis on Form 8949 1099-B, that inconsistency may trigger a notice. Noncovered means the IRS relies entirely on what you report — and you need to find the correct basis yourself from trade confirmations or account statements.
Wash Sales on Form 8949
A wash sale happens when you sell at a loss and buy the same or substantially identical security within 30 days before or after. The IRS disallows that loss for the current year — it gets deferred, not eliminated.
On Form 8949, a wash sale is reported with code W in Column (f) and the disallowed loss in Column (g) as a positive number. If you had a $500 loss but $200 was disallowed, you'd show W in (f), 200 in (g), and -300 in (h).
The deferred loss gets added to the basis of the replacement shares. Wash sales are one of the most common sources of Form 8949 errors because people either forget them or misread how the adjustment flows through the columns.
How Our Converter Helps with Form 8949
If your broker provides a 1099-B as a PDF, transferring all that data manually is tedious and error-prone. 1099-B Converter converts your PDF into structured formats — a TXF file for direct import into tax software, and a CSV file that serves as a clean worksheet.
The TXF format maps directly to the fields tax software uses to populate Form 8949. When you import a TXF into TurboTax, it reads the transaction details and places them in the correct columns — short-term vs. long-term, covered vs. noncovered, wash sales flagged. The software builds Form 8949 1099-B entries automatically.
The CSV is useful when you want to review data before importing or work with an accountant. Every column corresponds to a Form 8949 field — a human-readable worksheet. Less manual transcription means fewer transposed numbers, misread dates, and missed wash sales. Start with your 1099-B PDF here.
Common Form 8949 Mistakes
Mistake #1: Reporting the Wrong Box (A vs B vs C)
Every transaction must go under the right checkbox. Covered short-term goes under Box A, noncovered short-term under Box B. Putting a covered transaction under Box B creates a discrepancy between broker records and your filing — a common trigger for CP2000 notices.
Mistake #2: Using Wrong Cost Basis
For noncovered securities, your broker may have left the basis blank or listed it as zero. That doesn't mean your basis is zero. You still need to find your actual cost basis from trade confirmations. Filing with a zero basis when you paid $10,000 results in a massively overstated gain.
Mistake #3: Forgetting Wash Sale Adjustments
Brokers report wash sales on 1099-B, but when manually transcribing, it's easy to copy the loss without copying the disallowed amount. The result is a deduction you're not entitled to.
Mistake #4: Mixing Short-Term and Long-Term
Part I and Part II of Form 8949 are not interchangeable. Short-term transactions are taxed at ordinary income rates; long-term at preferential capital gains rates. Putting a long-term sale in Part I could cost you significantly more in taxes.
Mistake #5: Not Matching IRS Records
Your broker filed a copy of your 1099-B directly with the IRS. If your Form 8949 reports different proceeds or a different number of transactions, the discrepancy gets flagged. Proceeds and transaction count should align with what the IRS already received.
TurboTax and Form 8949
TurboTax and most major tax software build Form 8949 for you — you never open a blank copy and start typing. You import your transaction data, review it, and the software handles column placement, checkbox selection, and totaling.
The import options vary. You can import directly from supported brokers or upload a TXF file. The TXF format is a structured file that tax software reads to understand each transaction — description, dates, proceeds, basis, adjustment codes.
What matters is that the underlying data is correct before import. TurboTax will faithfully put bad data into the right columns. If proceeds are wrong, basis is missing, or wash sales aren't flagged, the software won't catch those issues — it enters what it receives.
Schedule D and Form 8949
Once Form 8949 is complete, the totals move to Schedule D. Short-term totals from Part I go to Schedule D lines 1b, 2, or 3. Long-term totals from Part II go to lines 8b, 9, or 10.
Schedule D nets your short-term gains and losses against each other, and does the same for long-term. The net short-term result is taxed at ordinary rates; the net long-term result gets preferential rates (0%, 15%, or 20% depending on income). The final net capital gain or loss flows to line 7 of Form 1040.
FAQ: Form 8949
Do I need to file Form 8949 if I had no gains?
Yes, if you had any capital asset sales — including losses. Losses are valuable because they can offset gains or up to $3,000 of ordinary income per year.
What if I have hundreds of transactions?
You can attach a substitute statement in lieu of listing every transaction individually, provided you include required totals on Form 8949. Most tax software handles this automatically.
Does crypto go on Form 8949?
Yes. Cryptocurrency disposals are reported on Form 8949 just like stock sales. The IRS treats crypto as property.
What if my broker shows a different basis than I calculated?
For covered securities, your broker's number is what the IRS has on file. Use Column (g) with an adjustment code to reconcile. For noncovered securities, you can report your own basis.
Can I skip Form 8949 and go straight to Schedule D?
Only in very limited circumstances — if all transactions are covered with no adjustments, some software summarizes directly on Schedule D. But in most cases, Form 8949 is required.
What's the deadline for Form 8949?
It's due with your federal return — April 15 in most years, or October 15 with an extension.
Bottom Line
The Form 8949 1099-B relationship is straightforward once you see it laid out: your broker's 1099-B contains the raw data, and Form 8949 presents it to the IRS in a structured format. Each column has a purpose, each box has a meaning, and the totals flow cleanly into Schedule D and your 1040.
The complexity isn't conceptual — it's operational. Moving data accurately from a PDF to a tax form without transposing digits or dropping wash sale adjustments is where errors happen. Having your 1099-B data in a clean format before you open TurboTax makes the whole process faster and less risky.
Use Our CSV as Your Form 8949 Worksheet — Upload your 1099-B PDF at 1099-B Converter and download a CSV that maps directly to Form 8949 fields. No account required.