Tax-loss harvesting sounds like something only wealthy investors do with their financial advisors. In reality, it’s a straightforward technique that any investor with a taxable brokerage account can use to reduce their tax bill — legally, without changing their long-term investment strategy. Here’s what it actually means and whether it makes sense for you.
What Is Tax-Loss Harvesting?
Tax-loss harvesting is the practice of selling an investment that has lost value in order to use that loss to offset gains — or even ordinary income — on your tax return. You’re not abandoning your investment strategy; you’re strategically realizing a loss on paper to reduce what you owe the IRS, then immediately reinvesting the proceeds in a similar (but not identical) asset.
The key word is harvesting: you’re capturing a loss that exists on paper and converting it into a real tax benefit before the year ends.
How It Works: A Simple Example
Say you invested $10,000 in an S&P 500 ETF earlier this year, and it’s now worth $7,500. You also sold some stock earlier in the year for a $3,000 profit.
- You sell the ETF at $7,500 — realizing a $2,500 loss
- That $2,500 loss offsets your $3,000 gain → your taxable gain drops to $500
- You immediately buy a similar (but not identical) ETF to maintain your market exposure
- You’ve saved taxes on $2,500 of gains while staying fully invested
At a 15% long-term capital gains rate, that’s $375 saved — for about 10 minutes of work.
To fully understand what you’re offsetting, see our guide on how capital gains tax works — short-term and long-term gains are taxed at very different rates.
The Wash-Sale Rule: The One Rule You Must Know
The IRS anticipated that investors would try to sell a losing position and immediately buy it back, so they created the wash-sale rule. It says: if you sell an investment at a loss and buy the same (or “substantially identical”) security within 30 days before or after the sale, the IRS disallows the loss deduction.
In plain terms: you can’t sell your Vanguard S&P 500 ETF (VOO) at a loss and immediately buy it back. The loss gets disallowed.
How to stay compliant:
- Sell VOO → buy a different S&P 500 ETF like iShares IVV or Schwab SCHB ✅
- Sell a tech stock → buy a tech sector ETF ✅
- Sell VOO → wait 31 days → buy VOO back ✅
- Sell VOO → immediately buy VOO back ❌ (wash sale — loss disallowed)
The 30-day window applies in both directions — 30 days before AND 30 days after the sale. If you bought more shares of the same fund 20 days before selling, the wash-sale rule can still apply.
What Losses Can Offset
Capital losses have a specific order of application under IRS rules:
- First: offset capital gains of the same type (short-term losses offset short-term gains; long-term losses offset long-term gains)
- Second: offset capital gains of the opposite type (excess short-term losses can offset long-term gains, and vice versa)
- Third: offset up to $3,000 of ordinary income per year (wages, freelance income, etc.)
- Fourth: any remaining losses carry forward to future tax years indefinitely
The $3,000 ordinary income deduction is particularly valuable: if you have more losses than gains, you can deduct $3,000 directly from your salary income, then carry the rest forward. A $10,000 net capital loss could save you $3,000/year in deductions for multiple years.
When Tax-Loss Harvesting Makes Sense
Tax-loss harvesting is most valuable in specific situations:
You have a taxable brokerage account
This is the most important prerequisite. Tax-loss harvesting does not apply to tax-advantaged accounts like a Roth IRA or Traditional IRA, or a 401(k). Gains and losses inside those accounts have no immediate tax consequences. You can only harvest losses in a regular, taxable brokerage account.
You have realized capital gains to offset
If you sold winning investments during the year, harvesting losses reduces what you owe. The higher your gains, the more valuable the harvesting.
You’re in a higher tax bracket
If you’re in the 0% capital gains bracket (taxable income under ~$47,025 for single filers in 2025), you already owe nothing on long-term gains — tax-loss harvesting adds no value. The higher your bracket, the more each dollar of loss is worth.
Year-end tax planning
December is the most common time to review your portfolio for harvesting opportunities, before the tax year closes. Many investors do a single annual review rather than monitoring throughout the year.
When Tax-Loss Harvesting Doesn’t Make Sense
You’re a long-term buy-and-hold investor with no gains
If you haven’t sold anything and don’t plan to, there’s nothing to offset. Harvesting losses against ordinary income ($3,000/year) is useful but requires actively managing your portfolio, which may conflict with a passive index fund strategy.
The tax savings don’t justify the complexity
If your portfolio is small (under $20,000–$30,000), the tax savings from harvesting are likely minimal. A $500 loss might save you $75 at a 15% rate — not nothing, but probably not worth the time and risk of violating the wash-sale rule.
You’d trigger a wash sale by accident
If you have automatic dividend reinvestment (DRIP) turned on or contribute regularly to your brokerage, you might accidentally trigger a wash sale without realizing it. Always check your recent purchase history before harvesting a loss.
You plan to sell the replacement investment soon
If you sell Fund A, buy Fund B to avoid the wash sale, and then sell Fund B 2 weeks later — you’ve just created a new taxable event. The strategy works best when you hold the replacement investment for at least a year.
Tax-Loss Harvesting vs. Tax-Gain Harvesting
There’s a lesser-known mirror strategy called tax-gain harvesting — intentionally realizing gains when you’re in a low tax year. If your income drops temporarily (between jobs, early retirement, taking a sabbatical), and you fall into the 0% capital gains bracket, you can sell appreciated investments tax-free and immediately rebuy them at the higher cost basis. This resets your cost basis upward, reducing future taxable gains.
Both strategies are about timing when you recognize gains and losses — not about changing what you own or how long you invest.
How Robo-Advisors Handle This Automatically
Platforms like Betterment and Wealthfront offer automated tax-loss harvesting as a built-in feature. Their algorithms scan your portfolio daily for harvesting opportunities, execute the trades, and reinvest in similar funds — all while monitoring for wash-sale violations. For investors who don’t want to manage this manually, it’s one of the most tangible benefits of using a robo-advisor.
Manual harvesting is completely viable for investors with simple portfolios (a handful of ETFs), but automated harvesting shines when you have a larger, more complex portfolio with many positions.
Real Example: The Math Over Time
Here’s how tax-loss harvesting compounds over a volatile market period:
| Year | Gains Realized | Losses Harvested | Taxable Gain | Tax Saved (15%) |
|---|---|---|---|---|
| 2023 | $4,000 | $3,500 | $500 | $525 |
| 2024 | $6,000 | $2,000 | $4,000 | $300 |
| 2025 | $2,500 | $4,000 | $0 + $1,500 carry | $375 |
| Total | $12,500 | $9,500 | $4,500 | $1,200 |
Over three years, the same investor who made $12,500 in gains only paid taxes on $4,500 — saving $1,200 at a 15% rate. That’s money that stayed invested and continued compounding.
Step-by-Step: How to Harvest a Loss
- Review your taxable brokerage account for positions currently worth less than you paid
- Check your realized gains for the year — what do you actually need to offset?
- Check recent purchases — did you buy the same fund within the last 30 days? (wash-sale risk)
- Sell the losing position and note the loss amount
- Immediately buy a similar but not identical replacement to maintain market exposure
- Record the transaction — your brokerage will send a 1099-B, but keep your own notes
- Report on Schedule D of your tax return (or let your tax software handle it)
For a refresher on how investment income gets reported at tax time, see our guide on how to file taxes for the first time.
Frequently Asked Questions
Does tax-loss harvesting work in a Roth IRA or 401(k)?
No. Tax-loss harvesting only applies to taxable brokerage accounts. Losses inside a Roth IRA or 401(k) have no tax consequence — but neither do gains. The tax shelter works in both directions.
What counts as a “substantially identical” security for the wash-sale rule?
The IRS definition is intentionally vague, but in practice: the same stock, the same ETF, or a fund that tracks the exact same index from the same provider is likely too similar. Two ETFs that track different indexes (S&P 500 vs. Total Market) or from different providers are generally considered distinct enough. When in doubt, consult a tax professional.
Can I harvest losses on crypto?
Yes — and unlike stocks, the wash-sale rule does not currently apply to cryptocurrency (as of 2025). You can sell Bitcoin at a loss and immediately rebuy it, capturing the tax loss without waiting 30 days. This may change with future legislation, but for now it’s a meaningful advantage for crypto investors.
How much can I deduct against ordinary income?
Up to $3,000 per year ($1,500 if married filing separately). Any excess carries forward indefinitely. There’s no expiration on carried-forward losses — you can use them in future years until they’re fully used up.
Is tax-loss harvesting worth it for small investors?
At small portfolio sizes (under $10,000–$20,000), the absolute tax savings are modest. A $1,000 loss saves roughly $150 at a 15% rate. It’s not harmful, but the complexity may outweigh the benefit. As your portfolio grows and you start realizing more gains, the strategy becomes progressively more valuable. Focus first on maxing out your tax-advantaged accounts (401(k), IRA) before optimizing a taxable account.
What if I have more losses than gains?
You can deduct up to $3,000 against ordinary income, and the rest carries forward to next year. In a year with significant market losses, this carry-forward can be a substantial asset — especially if you expect higher income (and therefore higher tax rates) in future years.
This article is for informational purposes only and does not constitute tax or financial advice. Tax laws change annually. Consult a qualified tax professional before making decisions based on tax-loss harvesting strategies.