Form 8949 instructions: which box applies (2026)

Form 8949 instructions say which box to check, and you check only one box on each page. A Form 1099-B sale is short-term box A when basis was reported to the IRS, box B when it was not, and box C when there is no Form 1099-B and the sale is not a digital asset. Long-term is box D, box E, or box F on those same facts. A Form 1099-DA digital asset is short-term box G when basis was reported, box H when it was not, and box I when there is no Form 1099-DA or Form 1099-B. Long-term is box J, box K, or box L. Do not use box C or box F for a digital asset. Schedule D then summarizes the Form 8949 totals.

Form 8949 generally lists each lot (or each aggregated group when the instructions allow) with date acquired, date sold, proceeds, cost basis, and codes for adjustments such as wash-sale disallowed losses. Short-term transactions and long-term transactions use different parts. Holding period is still the more-than-one-year test for most assets, with longer tests for QSBS and different character rules for collectibles and unrecaptured Section 1250 gain.

Schedule D totals Form 8949, nets short-term and long-term results, applies capital-loss limits, and sends the net figure to Form 1040. Form 8960 then computes NIIT when MAGI and net investment income require it. A 1031 exchange uses Form 8824; Section 121 excluded home-sale gain may be omitted from taxable income but still needs care when 1099-S is issued or part of the gain is taxable.

Covered securities usually show basis on 1099-B. Uncovered or transferred lots may show proceeds only. Dividend reinvestment, merger cash, and employee-stock basis from a W-2 inclusion are common adjustment sources. If you sell at a loss and buy a substantially identical security within 30 days, the wash-sale rule can disallow the loss and move it into replacement basis, that adjustment belongs on Form 8949 when required.

Crypto lots may arrive on 1099-DA or from wallet exports. Each disposal can be a separate 8949 line. Transfers between your own wallets are generally not taxable but must keep basis and holding period. Do not assume the wash-sale statute that applies to securities automatically applies to crypto treated as property; confirm current IRS guidance.

The calculator estimates federal tax, NIIT, and state tax on the lots you enter. It is not an e-file engine and does not print Form 8949. Use it to see whether a sale is short-term or long-term, whether Section 121, QSBS, or collectibles rates change the bill, and whether a loss carryover or extra income moves brackets.

Open the stocks calculator for brokerage lots, the crypto or real-estate landers for those assets, or a state combo page when residency is the question. Then export or screenshot the estimate for a CPA who will complete 8949 and Schedule D. Educational only.