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 — no broker reports these (why), so YOU add code W and the column (g) amount to the affected sale. Our TurboTax walkthrough shows the exact clicks.

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.