Year-End Wash-Sale Checklist (Tax Year 2026)

By Wash-Sale Guardian (who's behind it) · Published 2026-09-23 · Last updated 2026-10-02 · How the checker works

One page for traders with more than one brokerage account — keep it next to your December screen. The four dates that decide whether a tax-loss harvest survives, what to check before and after every loss sale in every account, and the January reconciliation that catches what your 1099-Bs may not show you.

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1 · Know your dates (2026 tax year)

Date	What it means
Mon Nov 30	Last loss sale you can re-buy within 2026. Sale date + 30 days lands on Dec 30, so day 31 — Dec 31, the last trading day — is the first clean re-buy. Harvest after today and the earliest clean re-buy of that ticker slips into January 2027.
Thu Dec 31	Last trading day of 2026. A loss counts for tax year 2026 only if it is TRADED by today — trade date governs, not settlement (IRS Publication 550). Dec 31, 2026 is a regular NYSE session.
Late Dec → January	The window does not respect New Year’s. Losses sold in late December are still washable by January re-buys — in any account. A Mon Jan 11 re-buy washes a Mon Dec 21 loss, off the 2026 return. Each window ends 30 days after its own sale: a Dec 18 sale’s ends Jan 17. For a Dec 31 sale it runs through Sat Jan 30, 2027, so Sun Jan 31 is the first clean calendar day and Mon Feb 1 the first trading day.
Mid-Feb	1099-Bs arrive. 1099-Bs are generally due Tue Feb 16 in 2027 (Feb 15 is a federal holiday). Box 1g only has to cover washes of covered securities with the same CUSIP inside that one account — anything beyond that is optional, so don’t count on it. The cross-account reconciliation is yours to do.

All of these follow from one fact: the wash-sale window is 61 days — 30 days before the loss sale, the sale day, and 30 days after — counted in calendar days, across every account you own.

2 · Before every harvest sale

Look BACKWARD 30 days, every account: did any account — yours, your spouse's, your IRAs — buy this ticker, including DRIP and auto-invest fills? A buy in the last 30 days washes the loss you're about to take. (Why every account counts.)
Kill the auto-buyers: pause dividend reinvestment and scheduled purchases for this ticker in EVERY account before selling — especially IRAs.
Pick a replacement that isn't substantially identical: a fund tracking a different index is the widely used safer swap; same-index swaps are a gray zone; a call option on the same ticker is a wash by statute (§1091: "a contract or option so to acquire").

3 · After every harvest sale (the 61-day discipline)

Write down the first clean re-buy date: sale date + 31 days. No account you or your spouse own may buy that ticker (or a call option on it) before then. The spouse rule has no filing-status condition — Pub 550 says simply that a purchase by your spouse makes it a wash sale.
Guard the IRA doubly: a re-buy inside your traditional or Roth IRA doesn't defer the loss — Rev. Rul. 2008-5 disallows it permanently, with no basis adjustment, and your 1099-B isn't required to show it. Your spouse's IRA is unsettled — treat it conservatively. (Full explainer.)
Late-December sellers: your window runs into January. A Monday January 11 re-buy washes a Monday December 21 loss — it comes off your 2026 return and moves into the new shares' basis.

Why the IRA case is different. An ordinary wash sale only defers the loss: the disallowed amount is added to the basis of the replacement shares, and you recover it when they're sold (IRS Publication 550). An IRA has no taxable basis to carry it, so the same re-buy made inside your traditional or Roth IRA destroys the deduction outright — and because brokers only have to report washes inside a single account, don't expect any 1099-B you receive to mention it.

4 · The reconciliation (after Jan 30, before the 1099-Bs arrive)

Export every account's full trade history through Jan 30, 2027 (CSV) — all brokers, all IRAs. Start no later than Dec 1, 2025, and early enough to include the purchase of every share you still held on that date: without those purchases the checker can't tell which lots your sales came from, and it withholds a symbol when it sees more shares sold than bought. A calendar-2026 export also misses the Jan 2027 re-buys that wash late-December losses and the Dec 2025 buys that wash early-January 2026 losses. Robinhood reports take 2–24 hours to generate; request early. Walkthroughs: Schwab, Fidelity, IBKR, E*TRADE.
Run the cross-account check and list the wash sales it finds in the trades you import, with their disallowed dollars and which lot's basis absorbs it.
Compare against each 1099-B in February: box 1g shows what that broker reported, and it can be higher or lower than your all-accounts figure. Where your figure differs, the Form 8949 instructions (code W) have you enter the correct amount in column (g); if it is lower than box 1g, attach a statement explaining the difference. Bring the summary to your CPA.

The one rule that prevents most of the damage: before ANY account buys a ticker between now and the end of January, ask "did any of my accounts sell this at a loss in the last 30 days — or might one sell it in the next 30?"

How to use this

Print the PDF (or bookmark this page) and tick sections 2 and 3 for every loss sale you make between now and Dec 31 — one pass per sale, per ticker.
Before any Q4 buy in any account, check whether a 30-day window is open on that ticker. The free checker shows each open window and the first day a re-buy no longer washes the loss, across the accounts you import; the spreadsheet template does the same by hand for a handful of sales.
After Jan 30, run section 4 once, before the 1099-Bs arrive, so February is a comparison rather than a scramble. Cross-account adjustments are yours to report — see entering them in TurboTax.

Sources: IRC §1091 · IRS Publication 550 · Rev. Rul. 2008-5 · Form 8949 instructions.

Frequently asked questions

When is the last day to tax-loss harvest for 2026?

Thursday, December 31, 2026 — the last trading day of the year. A loss belongs to tax year 2026 if the trade date is on or before Dec 31; the settlement date does not matter (IRS Publication 550). The wash-sale window keeps running, though: a re-buy of the same ticker in any of your accounts within 30 days after the sale disallows that December loss (for a Dec 31 sale, through Jan 30, 2027).

What is the last day to harvest a loss and still re-buy the same stock in 2026?

November 30, 2026. A loss sale on Nov 30 has its 30-day post-sale window end on Dec 30, so Dec 31 — the last trading day of the year — is the first day you may re-buy without washing the loss. Sell on Dec 1 or later and the first clean re-buy date falls in January 2027.

Does the wash-sale window reset on January 1?

No. The 61-day window is counted in calendar days straight across the year boundary. A re-buy on Monday, January 11, 2027 washes a loss sold on Monday, December 21, 2026: the disallowed amount comes off your 2026 return and moves into the basis of the new shares.

What happens if my IRA buys the stock I sold at a loss?

The loss is permanently disallowed. Under Rev. Rul. 2008-5, a replacement purchase inside your traditional or Roth IRA within the window gets no basis adjustment — unlike an ordinary wash sale, where the disallowed loss is added to the basis of the replacement shares and recovered when they are sold. A 1099-B isn’t required to show it, so don’t rely on one; it still belongs on your Form 8949 with code W.