Tax-Loss Harvesting and the Wash Sale Rule (2026 Guide)

Quick Answer: Harvesting Losses Without Triggering a Wash Sale

Tax-loss harvesting means selling a losing position in a taxable account to realize a capital loss. That loss offsets your capital gains dollar for dollar, and up to $3,000 of whatever is left offsets ordinary income. The rest carries forward indefinitely.

The wash sale rule (Internal Revenue Code Section 1091) is the constraint. If you buy the same or a “substantially identical” security within 30 days before or 30 days after the sale, a 61-day window in total, the loss is disallowed for that year. In a taxable account it isn’t destroyed: the disallowed amount is added to the basis of the replacement shares. Inside an IRA, it is gone for good.

Key Takeaways

The window is 61 days, not 30. Section 1091 counts 30 days before the sale, the sale date itself, and 30 days after. A purchase you made three weeks earlier can wash today’s sale.
The window does not reset at year-end. Sell on December 20, buy back on January 10, and you still have a wash sale.
$3,000 per year against ordinary income ($1,500 if married filing separately). That figure has not moved since 1978 and is not indexed for inflation.
What the loss is worth depends on what it offsets. Wiping out a short-term gain at 24% is worth far more than wiping out a long-term gain at 15%.
A repurchase inside your IRA is the one unrecoverable mistake. Rev. Rul. 2008-5 disallows the loss and does not add it to the IRA’s basis.
Your 1099-B only catches wash sales inside a single account. Two brokerages, a spouse’s account, or a 401(k) auto-purchase can create one that nothing on your tax documents flags.
The One Big Beautiful Bill Act changed none of this. The wash sale rule, the $3,000 limit, and the 0%/15%/20% capital gains structure are all unchanged for 2026.

How Tax-Loss Harvesting Actually Works

A loss on paper does nothing for your tax return. The IRS only recognizes realized losses, which means you have to sell. A position down 40% but still sitting in your account is worth exactly zero at tax time.

Two conditions have to be true for harvesting to do anything:

The account has to be taxable. Selling at a loss inside a 401(k), IRA, or HSA produces nothing. Those accounts don’t report gains or losses to your return in the first place.
You need something to offset. Capital gains, or ordinary income, or both.

The netting order

Losses don’t get applied wherever you want them. Schedule D nets them in a fixed sequence:

Short-term losses offset short-term gains.
Long-term losses offset long-term gains.
Any leftover in one category crosses over to offset the other.
Up to $3,000 of what remains offsets ordinary income.
Anything still left carries forward to next year.

The order matters because short-term gains are taxed at ordinary rates of 10% to 37%, while long-term gains get the preferential 0%, 15%, or 20% treatment covered in our 2026 capital gains rates guide. A harvested loss that kills a short-term gain is doing more work.

What a $3,000 deduction is worth

Most articles stop at “reduces your taxable income by up to $3,000.” Here is what it saves at each of the 2026 marginal rates:

Value of the $3,000 capital loss deduction by 2026 marginal tax bracket
Marginal Bracket	Tax Saved on $3,000
10%	$300
12%	$360
22%	$660
24%	$720
32%	$960
35%	$1,050
37%	$1,110

Now compare that to offsetting gains. A $10,000 loss applied against a $10,000 short-term gain for someone in the 24% bracket saves $2,400. The same $10,000 loss applied against a $10,000 long-term gain at 15% saves $1,500. Same loss, $900 difference, decided entirely by what it lands on.

Harvesting is a twelve-month activity

Nearly every article on this topic is written as a December checklist, and that habit costs money. Losses appear when markets fall, and markets don’t wait for the fourth quarter. A position that was down 22% in March and recovered by November was a harvesting opportunity that expired quietly.

Check your taxable account for unrealized losses a few times a year instead of once in the last week of December. That’s the whole difference.

The $3,000 Limit and Capital Loss Carryforwards

Losses offset capital gains with no cap at all. If you realize $200,000 of gains and $200,000 of losses in the same year, they cancel completely. The $3,000 ceiling only applies to net losses hitting ordinary income (wages, self-employment income, interest, and so on).

Worked example: an $18,000 loss

Say you realize $18,000 in losses and $6,000 in gains during 2026:

$6,000 of the loss offsets the gains in full. Tax on those gains: $0.
$3,000 is deducted against ordinary income on Form 1040.
$9,000 carries forward into 2027.

In 2027 that $9,000 offsets any gains you realize with no limit, and if you have none, another $3,000 comes off ordinary income. The remaining $6,000 rolls into 2028. There is no expiration date on a carryforward.

Details that trip people up

The limit is per return, not per account or per spouse. A married couple filing jointly gets $3,000 total, not $3,000 each. Filing separately drops each spouse to $1,500.
$3,000 is not inflation-indexed. It has been the same nominal figure since 1978. In real terms it shrinks every year.
Carryforwards die with the taxpayer. An unused capital loss carryover is personal to the taxpayer and does not pass to heirs or to a surviving spouse’s later separate returns. If someone is sitting on a large carryforward late in life, that’s a planning conversation worth having.

To see what a specific harvest does to your own numbers, the tax-loss harvesting calculator runs the netting order and the $3,000 limit for you.

The Wash Sale Rule: The 61-Day Window

Section 1091(a) disallows a loss on stock or securities if, “within a period beginning 30 days before the date of such sale or disposition and ending 30 days after such date,” you acquire substantially identical stock or securities.

Count it out: 30 days before, plus the day of the sale, plus 30 days after. 61 days. Most people remember “30 days” and only look forward, which is where the trouble starts.

The backward half of the window

This is the part that surprises people. If you bought more shares of a fund on March 1 and then sold your older, losing lot on March 20, that March 1 purchase falls inside the 30-day look-back and washes the sale. You didn’t buy anything after selling. You still triggered the rule.

Dollar-cost averaging into the same fund every month makes this almost automatic. If you contribute on the 1st of every month and harvest on the 15th, the previous purchase is always inside the window.

What counts as an acquisition

The rule is broader than “you placed a buy order.” All of these can trigger it:

Ordinary purchases in any of your taxable accounts
Contracts or options to acquire the security (Section 1091(a))
Dividend reinvestment (DRIP) purchases
Automatic payroll or 401(k) contributions buying the same fund
Purchases made by your spouse
Purchases by a corporation you control
Purchases inside your own IRA or Roth IRA

What happens when it triggers

The loss is disallowed for the current year. Under Section 1091(d), the disallowed amount is added to the cost basis of the replacement shares, and per Publication 550 the original holding period tacks on to the new shares.

So in a taxable account, a wash sale is a timing problem, not a lost deduction. Sell 100 shares at a $2,000 loss, rebuy inside the window at $5,000, and your basis in the new lot is $7,000. When you eventually sell those shares outside the window, the $2,000 comes back.

January 1 is not a reset

The window is a rolling 61 days measured from the sale date. It has nothing to do with the tax year. A December 20 sale and a January 10 repurchase is a wash sale, and the disallowed loss lands on the return for the year of the sale. December harvesters trip this constantly.

What “Substantially Identical” Means (and What It Doesn’t)

The statute uses the phrase and never defines it. IRS Publication 550 says only that you “must consider all the facts and circumstances in your particular case.” There is no safe-harbor list.

The clear cases

Not substantially identical: common stock of two different issuers, even direct competitors in the same industry. Selling Coca-Cola and buying PepsiCo is not a wash sale.
Generally not identical: bonds or preferred stock of the same issuer as its common stock, unless they’re convertible into the common on substantially similar terms.
Clearly identical: the same ticker, in any account you or your spouse control.

The fund question

Mutual funds and ETFs are where the ambiguity lives, and where most harvesting happens. The practitioner framework, which is convention rather than law, runs like this:

Two funds tracking the same index (an S&P 500 fund from one sponsor swapped for an S&P 500 fund from another) are the risky case. They hold the same securities in the same weights. The Kitces analysis of this question is the standard industry reference, and even it treats the answer as unsettled commentary rather than authority.
Two funds tracking different indexes in the same asset class (an S&P 500 fund swapped for a total-market or Russell 1000 fund) is the standard harvesting swap. Different index, different holdings.

The honest answer on the SPY-to-VOO style swap is that the IRS has never ruled on it and no court has decided it. Plenty of people do it. That isn’t the same as knowing it’s safe. If certainty matters more to you than staying invested in that exact index, don’t do it.

Four clean ways around the problem

Wait 31 days. Simple, and you accept 31 days of market exposure risk.
Swap to a different-index fund in the same asset class. Stay invested, keep your allocation, avoid the argument entirely.
Double up first. Buy the replacement lot, wait 31 days, then sell the original losing lot. The purchase is now outside the look-back window.
Harvest into a broad proxy. Move into a sector or asset-class fund for the 31 days, then rotate back if you want the original position.

Where People Break the Rule Without Knowing

These are the failures that show up in real returns, not the textbook ones.

The cross-broker gap

Form 1099-B, Box 1g reports “wash sale loss disallowed,” but the broker reporting rules are much narrower than the rule you actually have to follow. Brokers are only required to flag a wash sale when the loss sale and the repurchase happen in the same account and involve the identical security, matched by CUSIP. Section 1091 applies to substantially identical securities across every account you and your spouse control.

So sell at a loss at Broker A, buy the same fund at Broker B two weeks later, and neither 1099-B will flag anything. The same is true for a taxable-to-IRA repurchase at the same firm.

You are still legally responsible for identifying and reporting it. Your tax documents will look clean while your return is wrong.

Your spouse’s account

Publication 550 is explicit that if you sell stock at a loss and your spouse, or a corporation you control, buys substantially identical stock inside the window, you have a wash sale. It doesn’t matter that the purchase sat in their own account at a different firm. Separate logins do not create separate taxpayers here.

The IRA trap

This is the expensive one. Rev. Rul. 2008-5 holds that if you sell a security at a loss in a taxable account and buy it inside your IRA or Roth IRA within the window, the loss is disallowed and Section 1091(d) does not increase the IRA’s basis.

A pre-tax account has no basis to restore, so the deduction is destroyed rather than deferred. It’s the only version of a wash sale with no recovery path, which is why an IRA rebalance and a taxable harvest should never happen in the same month without checking tickers.

Automatic reinvestment

DRIP settings and payroll-driven 401(k) purchases run on their own schedule. A quarterly dividend reinvesting three weeks after you harvested the same fund is a wash sale on the reinvested amount. Turning off automatic reinvestment before a planned harvest takes about ninety seconds.

Partial wash sales

Only the shares matched to a repurchase get washed. Sell 1,000 shares at a loss and buy back 200 inside the window, and 80% of the loss survives untouched. The disallowed 20% attaches to the basis of the 200 replacement shares.

Crypto, Reporting, and Whether Harvesting Even Helps You

Digital assets and Section 1091

Section 1091 applies to “stock or securities.” The IRS treats digital assets as property, not securities, so a direct sale and immediate repurchase of the same token is not a wash sale under current law. You can sell Bitcoin at a loss and rebuy it the same hour.

Crypto ETFs and crypto-related equities are securities, though, so the wash sale rule fully applies to them. Selling a spot Bitcoin ETF at a loss and rebuying it two days later is an ordinary wash sale. Selling Bitcoin directly is not.

Bills extending the wash sale rule to digital assets have been drafted repeatedly, and none has been enacted so far. That’s live legislative risk, so confirm the current rule before you rely on it for a 2026 trade. Our Form 1099-DA guide covers the broker reporting side.

Reporting it on your return

Every harvested loss flows through Form 8949, then Schedule D, then to Form 1040. For a wash sale specifically:

Report the sale on the appropriate Form 8949 part (short-term or long-term).
Enter code W in column (f).
Enter the disallowed amount as a positive number in column (g).
Column (h) shows the allowed loss after the adjustment.

Totals carry to Schedule D. The net loss deduction, capped at $3,000 ($1,500 if married filing separately), lands on Form 1040. Any carryforward is tracked on the Capital Loss Carryover Worksheet in the Schedule D instructions, and you’ll need last year’s Schedule D to fill it out. Keep those returns.

When harvesting is the wrong move

Harvesting is sold as pure upside. It isn’t. Skip it, or think twice, when:

You have no gains and you’re in a low bracket. A $3,000 deduction at 10% is $300. If harvesting means selling out of a position you actually want, $300 is thin compensation.
You’re in the 0% long-term bracket. With taxable income at or under $49,450 (single) or $98,900 (married filing jointly), harvesting gains to reset your basis higher usually beats harvesting losses.
The loss is small. Bid-ask spreads, a 31-day gap in market exposure, and the paperwork can outweigh a few hundred dollars of deduction.

There’s also a tradeoff nobody mentions. Harvesting a $10,000 loss and buying a replacement lowers your basis by $10,000, so a future sale carries a $10,000 larger gain. The benefit is real, but it comes from four specific places: deferral, the rate arbitrage of offsetting a 24% short-term gain now and paying 15% later, the $3,000 annual ordinary-income offset, and a possible step-up in basis at death that erases the deferred gain entirely.

What it does to your return depends on your gains, your bracket, and everything else on the 1040. Tax47 lets you enter 1099-B amounts alongside your W-2 and Schedule C income and watch the estimated refund move, so you can test a $10,000 harvest in August instead of guessing in December. Pair it with the capital gains tax calculator and, if your income is near the surtax line, the NIIT calculator.

Sources & References

26 U.S. Code Section 1091 (Loss from wash sales of stock or securities): statutory text of the 30-day window, the basis adjustment rule, and the treatment of options and short sales.
IRS Publication 550 (Investment Income and Expenses): wash sale mechanics, the facts-and-circumstances standard for “substantially identical,” and holding-period tacking.
IRS Topic No. 409 (Capital Gains and Losses): the $3,000 / $1,500 annual limit, indefinite carryforward, and the 0%/15%/20% long-term rate structure.
IRS Revenue Ruling 2008-5: holds that a wash sale replacement purchased inside an IRA or Roth IRA permanently disallows the loss with no basis increase.
IRS Instructions for Form 8949: adjustment code W and reporting the disallowed amount in column (g).
IRS Revenue Procedure 2025-32 (2026 Inflation Adjustments): 2026 capital gains thresholds, ordinary brackets, and standard deduction amounts.
Investor.gov (SEC) Wash Sales glossary entry: plain-language regulator definition of a wash sale.

This article is for educational purposes only and is not tax, legal, or financial advice. Calculators and examples produce estimates only. Tax rules change periodically, always check current IRS guidance or consult a qualified tax professional.

Frequently Asked Questions

What is the wash sale rule in simple terms?

If you sell a stock or fund at a loss and buy the same or a substantially identical security within 30 days before or after that sale, the IRS disallows the loss on that year's return. The window is 61 days total: 30 before, the sale day, and 30 after.

How many days do I have to wait to buy back a stock I sold at a loss?

31 days after the sale date. Buying on day 31 or later is outside the window. Remember the rule also looks 30 days backward, so a purchase you made shortly before the sale can trigger it too.

Do I lose the money if I trigger a wash sale?

In a taxable account, no. The disallowed loss is added to the cost basis of the replacement shares, and the old holding period carries over, so you recover the benefit when you eventually sell those shares. The exception is a repurchase inside an IRA or Roth IRA, where Rev. Rul. 2008-5 says the loss is disallowed with no basis increase. That loss is gone permanently.

Can I sell one S&P 500 fund and buy a different one?

The IRS has never defined substantially identical for funds, and Publication 550 says it depends on all the facts and circumstances. The common practitioner line is that two funds tracking the same index are the risky case, while a fund tracking a different index in the same asset class is the standard harvesting swap. If you want certainty, wait 31 days or switch indexes.

How much can I deduct in capital losses each year?

Losses first offset capital gains with no limit. After that, you can deduct up to $3,000 of remaining net loss against ordinary income ($1,500 if married filing separately). Anything left over carries forward to future years indefinitely.

Does the wash sale rule apply to cryptocurrency?

Not to direct crypto sales. The IRS treats digital assets as property rather than stock or securities, and Section 1091 applies only to stock or securities. Crypto ETFs and crypto-related stocks are securities, so the rule fully applies to those. Congress has repeatedly drafted bills to extend the rule to digital assets, so confirm the current law before relying on it.

Does the wash sale rule reset on January 1?

No. The 61-day window runs continuously across the year boundary. Selling on December 20 and repurchasing on January 10 is still a wash sale.

Will my broker tell me if I had a wash sale?

Only partly. Brokers are required to report a wash sale in Box 1g of Form 1099-B when the loss sale and the repurchase happen in the same account and involve the identical security. Wash sales spanning two brokers, your spouse's account, or your IRA won't show up anywhere on your tax documents, and you're still responsible for reporting them.

Is tax-loss harvesting worth it if I have no capital gains?

It can be. You can still deduct up to $3,000 against ordinary income and carry the rest forward. But the benefit scales with your bracket, and harvesting lowers your basis, which raises a future gain. If you're in the 0% long-term capital gains bracket, harvesting gains may beat harvesting losses.