Form 8949 code W: the wash-sale adjustment

Code "W" in column (f) of Form 8949 tells the IRS a sale's loss is partly or fully disallowed as a wash sale, with the disallowed amount entered as a positive number in column (g) — per the Form 8949 instructions. The row's reportable loss shrinks by that amount; the deferred loss lives on in the replacement lot's basis (how the deferral works).

When it's automatic vs when it's on you

• Automatic: same-account washes your broker reported in 1099-B box 1g. Tax software imports these and applies code W for you.
• On you: washes across brokers, against your spouse's accounts, or into IRAs. Brokers must report only same-account washes (they may report more, but none can see your accounts at other brokers; why), so check what your 1099-B shows and add code W and the column (g) amount to the affected sale yourself for whatever it leaves out. Our TurboTax walkthrough shows where the number goes.

Two things to remember

1. Column (g) is positive for wash sales. A $2,000 disallowed loss = code W + $2,000 in (g), turning a −$2,000 row into $0.
2. Keep your own basis records. The replacement lot's broker doesn't know its basis went up; when you sell it, you'll adjust that future row too (typically code B). For IRA replacements there is no basis to adjust — the loss is permanently gone.

Finding the cross-account violations that belong on this form is the hard part — our free checker lists them with exact dollar amounts from your broker CSVs, in your browser.

Related: 1099-B doesn't match your records?