Tax-Loss Harvesting Before December 31: The 61-Day Wash-Sale Rule That Can Erase Your Deduction

Selling at a Loss Is Easy. Keeping the Tax Benefit Is the Hard Part.

A 61-day rule can decide whether a loss you harvest before December 31 is allowed, and 30 of those days come before you sell. Harvesting can turn a loss into a potential tax benefit, but buying a substantially identical security inside that window can disallow it. If you sell at a loss on December 10, for example, your window runs from November 10 through January 9.

This guide is about losses only: stocks and ETFs held in U.S. taxable brokerage accounts. It is not a general year-end tax overview, and selling before December 31 does not automatically produce a tax benefit. Whether a loss helps depends on the wash-sale rule, your other capital gains and losses, and the annual limits covered below. Everything here is general educational information, not individualized tax advice.

Four Numbers to Know Before You Harvest a Loss

Number	What it measures
61 days	Total wash-sale window, sale date included: 30 days before, the sale date, 30 days after
$3,000	Annual federal limit on a net capital loss deducted against other income
$1,500	The same annual limit if you file Married Filing Separately
No fixed expiration	Federal capital-loss carryforward for unused losses

The wash-sale window determines how a loss is treated; the deduction limit determines how an eligible net loss may be used. The $3,000 and $1,500 figures cap a deduction; they are not credits and not guaranteed refunds. All four figures reflect federal rules as of October 21, 2026, and the limits and carryforward come from IRC §1211 and IRC §1212.

The 61-Day Window Starts Before Your Sale

The wash-sale rule in IRC §1091 can disallow a loss when you sell stock or securities at a loss and acquire substantially identical stock or securities, or a contract or option to acquire them, during the 30 days before or the 30 days after the sale. The sale date counts too, so the window is 61 calendar days.

• D-30: the window opens, 30 days before the sale
• D: the sale date, which sits inside the window
• D+30: the window closes, 30 days after the sale

The arithmetic is 30 + 1 + 30 = 61 calendar days. To find your own window, subtract 30 days from your sale date and add 30 days to it. For a loss sale on December 10, that gives November 10 through January 9. Think of it as a 61-day fence around the sale: a purchase anywhere inside it counts, on either side of the sale date.

The days before the sale count as much as the days after: a purchase on November 10, or any later day before a December 10 sale, falls inside the window. Waiting 31 days after the sale does not cure a purchase made during the 30 days before it. My read: a late-December sale could make the after-sale half easy to overlook, because those 30 days run into the new year.

Your sale can then land in one of three outcomes, detailed in the next section:

• No wash sale: the ordinary capital-loss rules apply
• Taxable-account wash sale: the loss is generally deferred
• IRA or Roth IRA repurchase: the loss can be permanently unavailable

"Substantially identical" is a legal standard, not a comparison of ticker symbols. A different ticker does not by itself settle the question, and there is no IRS safe-harbor list of ETF combinations. IRS Publication 550 discusses wash sales in more detail.

What Happens to Your Loss in Each Scenario?

The same sale can end three ways, and only one of them can make the loss permanently unavailable.

Scenario	What happens to the loss	Basis and holding period	Deferral or permanent?
1. No wash sale	Deduction potentially available under ordinary rules; netting, the annual limit and carryforward then apply	No wash-sale adjustment	Nothing disallowed, so nothing deferred
2. Taxable-account wash sale	Deduction disallowed for that transaction	Disallowed loss generally added to the replacement securities' basis; original securities' holding period carries over	Deferral: generally deferred, not destroyed
3. IRA or Roth IRA repurchase	Disallowed under Rev. Rul. 2008-5	No corresponding basis increase inside the IRA	Can be permanently unavailable as a deduction

Taxable account: deferral. The disallowed loss is generally added to the cost basis of the replacement securities, and the holding period of the original securities carries over, so the loss is generally deferred, not destroyed. My read: the higher basis could reduce a future gain, or increase a future loss, when you sell the replacement securities.

IRA or Roth IRA: potentially permanent. Under Rev. Rul. 2008-5, a replacement purchase made in your IRA or Roth IRA disallows the loss, and there is no corresponding basis increase inside the IRA. The loss can therefore be permanently unavailable as a deduction. That permanent-loss risk belongs to this situation specifically; it is not a feature of every wash sale. My read: this could make a retirement-account purchase the costliest way to trigger the rule.

A $10,000 Capital Loss Can Produce Two Very Different Tax Outcomes

Both cases below are rule-of-thumb illustrations, not a forecast. They start from the same $10,000 net capital loss and apply different facts, so read them separately.

First, how a net loss gets used. Net capital losses first offset capital gains: short-term against short-term, long-term against long-term, then across the two. A remaining net capital loss can offset up to $3,000 of other income per year ($1,500 if Married Filing Separately). Unused losses carry forward under the federal rules with no fixed expiration and keep their short-term or long-term character.

Formula to plug in your own numbers: estimated tax savings (estimate) = (loss used against gains × tax rate on those gains) + (loss used against other income × your marginal ordinary-income rate), with the loss used against other income capped at $3,000 ($1,500 if Married Filing Separately). Carryforward = net loss minus loss used this year. In percent terms, each dollar of loss used saves roughly your tax rate on that dollar. In dollar terms, the savings depend on how many dollars of loss you can use this year.

Case A: the loss offsets a capital gain.

• Assumptions: a $10,000 net capital loss, a $10,000 long-term capital gain to offset, and an assumed 15% rate on that gain.
• Dollar math (estimate): $10,000 × 15% = $1,500 estimated tax savings.
• Percent math: the assumed 15% rate applies to every dollar of loss used, and all $10,000 is used.
• Chain: $10,000 loss → offsets $10,000 gain → about $1,500 saved.

Case B: no gains to offset.

• Assumptions: a $10,000 net capital loss, no capital gains to offset, an assumed 22% marginal ordinary-income rate, and the $3,000 annual limit.
• Dollar math (estimate): $3,000 × 22% = $660 estimated first-year tax savings, with $7,000 carried forward ($10,000 minus $3,000).
• Percent math: the assumed 22% rate applies to each dollar used, but only $3,000 of the $10,000 is usable in year one.
• Chain: $10,000 loss → $3,000 annual limit → about $660 saved, $7,000 carried forward.

Illustrative estimates only: Both examples use assumed tax rates and simplified facts. Actual tax savings depend on the taxpayer's full tax situation, including other capital gains and losses, applicable rates, filing status and other relevant rules. These calculations are not guaranteed tax savings.

Both cases assume the loss survives the wash-sale rule. If a wash sale disallows the loss, the savings in both cases do not apply to that transaction.

Check These Accounts and Transactions Before You Sell

Brokers generally report wash sales within one account, but the rule itself is not limited to one account. Review each item below across the full 61-day window.

• Your taxable brokerage accounts: list every purchase of the same or a substantially identical security within 30 days before and 30 days after the planned sale date.
• Traditional IRA: a replacement purchase here can disallow the loss with no basis increase, as Rev. Rul. 2008-5 describes.
• Roth IRA: the same Rev. Rul. 2008-5 treatment applies to a Roth IRA.
• Your spouse's accounts: a purchase by your spouse can also create a wash sale.
• Joint accounts: include them in the review, since a purchase there could count as yours.
• DRIP dividend reinvestment: a reinvestment that lands inside the window counts as an acquisition.
• Automatic or recurring investing: scheduled purchases count as acquisitions too, so check for buys inside the window.
• Options and acquisition contracts: a contract or option to acquire substantially identical securities counts under the statute.
• Accounts at other brokers: your selling broker's report generally will not reflect purchases made elsewhere.
• Entities you control: a purchase by a corporation or other entity you control can also create a wash sale.

Broker wash-sale reporting is generally limited to the same account and the same CUSIP, the identifier for a specific security, as IRS Publication 550 describes. A broker not flagging a transaction is not proof that no wash sale occurred, so the cross-account review is your job.

Can You Sell One ETF and Buy Another Tracking the Same Index?

A similar fund can look like an easy way to stay invested after a loss sale, but whether it works depends on whether the replacement is substantially identical, a legal standard. No IRS safe harbor guarantees that two different ETFs are not substantially identical.

The six factors below are analytical comparison points to investigate. They are not an official IRS test, and no combination of answers creates a safe harbor.

Factor	Question to investigate
Index	Do the two funds track the same index, or only similar ones?
Holdings	How closely do the actual securities held by the two funds match?
Methodology	Do the funds select and weight securities by the same rules?
Overlap	How much of one fund's portfolio also appears in the other?
Objective	Do the funds state the same investment objective?
Structure	Do the funds share the same legal structure and method of tracking the index?

My read: the more of these questions that come back "the same," the harder it could be to argue that two funds are different investments. Keep the fund documents you compared with your trade records.

ETF swapping is a strategy for managing uncertainty, not an IRS-guaranteed wash-sale exemption. This article does not recommend any fund pair and does not call any pair safe.

Crypto Tax-Loss Harvesting in 2026: What the Wash-Sale Rule Covers

Crypto sidebar. As of October 21, 2026, ordinary cryptocurrency is generally treated as property for federal tax purposes under IRS Notice 2014-21, so it is not subject to §1091 as stock or securities. A digital asset that qualifies as a stock or security, such as a tokenized security, can be treated differently, and the Schedule D instructions expressly address wash-sale treatment for applicable tokenized securities. Check which category your asset falls into before assuming the wash-sale rule does not apply.

A proposal could change the picture for traded digital assets. Section 301 of H.R. 10357, the Digital Asset Tax Certainty Act, would expand wash-sale treatment to them. The bill passed the House Ways and Means Committee on September 16, 2026, by a 38-5 vote, with a proposed effective date for dispositions after September 14, 2026. You can follow its status on Congress.gov.

H.R. 10357 is not law yet.

A Rising Index Doesn't Mean Every Tax Lot Is Profitable

One objection runs like this: if a major index is rising, there are no losses worth harvesting.

An index's return is not the return of every stock, sector or tax lot. It summarizes many holdings, so individual holdings can sit above or below it, and some can sit at a loss. Investors who bought the same security at different times also hold different unrealized gains and losses in it. Even inside one account, purchases of the same fund made at different times can sit at different gains and losses.

My read: a headline number is the wrong starting point for harvesting. The right one is your own cost-basis and unrealized gain/loss report, which shows lot by lot what you paid and what each lot is worth as of the report date.

The objection has a fair core: if your report shows no unrealized losses, there is nothing to harvest, and nothing here is a reason to sell anything. You just cannot read your own lots from a market headline.

Your Year-End Tax-Loss Harvesting Checklist

Work from top to bottom: first the facts, then the window, then execution and records.

Save this checklist

• Download the brokerage unrealized gain/loss report for each taxable account.
• Identify tax lots and cost basis for every position that shows a loss.
• Review realized short-term and long-term gains and losses for the year so far.
• Review any existing capital-loss carryforward from earlier years.
• Check acquisitions in the preceding 30 days of the same or substantially identical securities.
• Review planned acquisitions in the following 30 days, including anything already scheduled.
• Check IRA, Roth IRA, spouse and joint accounts for purchases inside the window.
• Review DRIP, automatic purchases, options and contracts that could count as acquisitions.
• Assess any replacement investment without assuming a safe harbor, because there is no IRS safe-harbor list of ETF combinations.
• Verify execution and tax reporting: confirm trades executed as planned and are reported as expected.
• Save trade confirmations and tax-lot records with your tax files.
• Reconcile Form 1099-B with Form 8949 and Schedule D, using the Form 8949 instructions and the Schedule D instructions.

Carryforward. To find last year's carryforward amount, start with the prior-year Schedule D and the Capital Loss Carryover Worksheet in the IRS instructions. Do not assume a brokerage display equals the official carryforward.

Your one next action: download the current unrealized gain/loss report and reconcile it against the prior 30 days of transactions before deciding whether any position warrants further tax review. This is an information-gathering step, not a recommendation to sell any security.

Official Rules, Important Limits and Further Reading

Rules and figures in this article reflect the sources below as of October 21, 2026.

• IRS Publication 550: IRS wash-sale guidance, including spouse and controlled-entity purchases, dividend reinvestment and broker reporting limits.
• IRC §1091: the statute that sets the wash-sale rule and its 30-day windows.
• IRC §1211: the limit on deducting net capital losses against other income.
• IRC §1212: the carryforward of unused capital losses.
• Rev. Rul. 2008-5: the IRS ruling on replacement purchases inside an IRA or Roth IRA.
• Schedule D instructions: reporting capital gains and losses, including wash-sale treatment of applicable tokenized securities.
• Form 8949 instructions: instructions for the form used to reconcile Form 1099-B transactions before they reach Schedule D.
• Notice 2014-21: the IRS notice treating virtual currency generally as property.
• H.R. 10357 on Congress.gov: the Digital Asset Tax Certainty Act, including §301; check the page for current status.
• 2025 NJ-1040 instructions: New Jersey's instructions, including Schedule NJ-DOP.

State taxes. Federal carryforward treatment should not be assumed to apply identically at the state level. For New Jersey, the 2025 NJ-1040 instructions (Schedule NJ-DOP) state that when the netted amount is a loss, the taxpayer enters zero and makes no entry on the corresponding NJ-1040 line. New Jersey's individual income-tax calculation does not necessarily provide the same benefit as the federal capital-loss carryforward; check the applicable NJ-1040 instructions.

If you are also considering selling profitable investments before year-end, read our 2026 tax-bracket and capital-gain-harvesting guide for the separate rules that may apply.

This article is for general educational purposes and is not individualized tax, legal or investment advice. Tax treatment depends on the facts of the transaction and the taxpayer's overall circumstances. Consider consulting a qualified tax professional before acting.