Quick answer. Most 1099-DA mismatches come from three things: basis that brokers aren't required to report (anything acquired before 2026, or transferred in), proceeds shown after fees, and small stablecoin or NFT sales left off under optional rules. Tick what applies below to see which ones fit your form.
Check your 1099-DA
Tick what applies to see the likely reasons.
What the IRS rules say
Start dates
The IRS broker reporting FAQ says reporting on Form 1099-DA begins "with transactions on or after January 1, 2025." Under the 2026 Form 1099-DA instructions, a covered security is a digital asset acquired after 2025 in a custodial account and held there until it's sold, and brokers must report basis (box 1g) only for covered securities. Basis for noncovered assets is voluntary, and the broker may check box 9.
The boxes that cause most mismatches
- Box 1f: gross proceeds, reduced by transaction costs.
- Box 1g: cost or other basis (covered securities only).
- Box 2: checked when basis is reported to the IRS.
- Box 9: noncovered security.
- Boxes 12a and 12b: units transferred into the account and the transfer-in date.
- Applicable checkbox on Form 8949: a code that tells you which Form 8949 box the broker expects, including a code for an unknown holding period.
The broker FAQ adds that when coins come in from another broker, the receiving broker isn't permitted to use the sending broker's information to report basis.
Stablecoins and NFTs
The 1099-DA instructions include optional methods: designated sales of qualifying stablecoins aren't reported if a customer's total gross proceeds "do not exceed $10,000 for the year" (above that, the broker reports an aggregate for each stablecoin type), and sales of specified NFTs aren't reported if total gross proceeds "do not exceed $600 for the year." A sale left off a 1099-DA can still belong on your return.
How a 1099-DA ties to Form 8949
| What the 1099-DA shows | Short-term (Part I) | Long-term (Part II) |
|---|---|---|
| Basis shown and reported to the IRS | Box G | Box J |
| No basis, or basis not reported to the IRS | Box H | Box K |
| No 1099-DA received | Box I | Box L |
From the 2025 Form 8949 instructions: don't use boxes C or F for digital assets. Enter the proceeds shown on the form in column (d). If basis reported to the IRS is wrong, keep it in column (e) and fix it in column (g) with code B; costs the form doesn't reflect use code E. If the form shows basis reported, no adjustments are needed and the Ordinary box isn't checked, Exception 1 lets you put the totals straight on Schedule D. The holding period is generally more than 1 year for long-term.
Sources
- IRS: Frequently asked questions about broker reporting (digital assets)
- IRS: Instructions for Form 1099-DA (2026)
- IRS: Instructions for Form 8949 (2025)
- IRS: Digital assets
Sources checked November 2026.
An organizer and calculator only: general information checked November 2026 against the official sources above, not tax or legal advice. It doesn't decide what you qualify for or owe. MCC Solutions is not affiliated with the IRS, CMS, Medicare, HealthCare.gov or Get Covered New Jersey. The tool runs in your browser, and nothing you enter is sent or saved.
Common questions
When did Form 1099-DA start?
The IRS says brokers report digital asset sales on Form 1099-DA beginning with transactions on or after January 1, 2025, so the first forms cover 2025 sales.
Why is the cost basis blank on my 1099-DA?
Brokers must report basis only for covered securities: digital assets acquired after 2025 in that custodial account. Coins bought earlier, or moved in from another wallet or exchange, are usually noncovered, and the basis box can be blank or box 9 checked.
Which Form 8949 box do I use for a 1099-DA sale?
The 2025 Form 8949 instructions use box G (short-term) or J (long-term) when the form shows basis reported to the IRS, H or K when it shows no basis or basis not reported, and I or L when you got no 1099-DA.
Will small stablecoin or NFT sales be on the form?
Maybe not. Under optional methods in the 1099-DA instructions, designated qualifying stablecoin sales aren't reported if the year's total is $10,000 or less, and specified NFT sales aren't reported if the year's total is $600 or less.
Why are the proceeds on my 1099-DA lower than my sale price?
Box 1f is gross proceeds reduced by transaction costs. If your own records show the price before fees, the numbers will differ by the fees.
My basis on the form is wrong. What do the instructions say?
For a sale in box G or J, the Form 8949 instructions say to enter the basis shown on the form in column (e) and correct it in column (g) using code B. Ask a tax professional if you're unsure.
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