FinanceFirst financial glossary
What is Tax-Loss Harvesting?
A direct definition, followed by examples, comparisons, related concepts, and the sources that support the explanation.
Written by Asim Ahmad, Founder and Editor, FinanceFirst
Definition
In one sentence about Tax-Loss Harvesting
Tax-loss harvesting is the strategy of selling investments at a loss to offset capital gains and reduce your tax bill. If your losses exceed your gains, you can deduct up to $3,000 of net losses against ordinary income per year, with any remaining losses carrying forward to future years indefinitely.
Why Tax-Loss Harvesting Matters
Tax-loss harvesting can save investors hundreds or thousands of dollars in taxes each year. By strategically realizing losses, you offset gains that would otherwise be taxed at rates up to 37% (short-term) or 20% (long-term). Even in years without gains, the $3,000 annual deduction against ordinary income provides a direct tax benefit. Over a 20-year investing period, consistent tax-loss harvesting and reinvesting the tax savings can add an estimated 0.5% to 1.5% to annual after-tax returns, according to research by Vanguard and Wealthfront. The strategy is most valuable in volatile markets when some positions are temporarily down, and it works best in taxable brokerage accounts (not in tax-deferred accounts like 401(k)s or IRAs, where gains are not taxed annually).
Real-World Example: Harvesting a Loss to Offset Gains
An investor in the 24% federal bracket sells Stock A for a $10,000 long-term gain. They also hold Stock B, which is down $7,000 from its purchase price:
| Action | Amount | Tax Impact |
|---|---|---|
| Sell Stock A (long-term gain) | +$10,000 gain | $1,500 tax at 15% rate |
| Sell Stock B (harvest the loss) | -$7,000 loss | Offsets $7,000 of gain |
| Net capital gain after harvesting | $3,000 | $450 tax at 15% rate |
| Tax saved by harvesting | $1,050 saved | |
| Buy similar (not identical) ETF | $7,000 reinvested | Stay invested in the market |
Tax-Loss Harvesting Rules and Limits
Key rules governing how tax losses can be used:
| Rule | Details | Example |
|---|---|---|
| Loss offset order | Short-term losses offset short-term gains first; long-term losses offset long-term gains first; then cross-type netting | $5K ST loss offsets $5K ST gain, then excess offsets LT gains |
| Annual deduction limit | Up to $3,000 in net capital losses can offset ordinary income ($1,500 if married filing separately) | $8K net loss = $3K deducted this year + $5K carried forward |
| Carryforward | Unused net capital losses carry forward indefinitely to future tax years | $5K carryforward used to offset gains in any future year |
| Wash-sale rule | Cannot repurchase the same or substantially identical security within 30 days before or after the sale | Sell S&P 500 ETF (SPY) at a loss, buy a total market ETF (VTI) instead |
When Tax-Loss Harvesting Applies
Tax-loss harvesting is most effective in these situations:
- When you have realized capital gains from selling investments, and you hold other positions that are currently at a loss
- During market downturns or corrections when many portfolio positions are temporarily below their cost basis
- When you want to rebalance your portfolio and can strategically sell underperforming positions to capture losses
- In taxable brokerage accounts only (this strategy provides no benefit in tax-deferred accounts like 401(k)s or IRAs)
- When you can replace the sold investment with a similar but not substantially identical fund to maintain market exposure
- Near year-end when reviewing your tax situation and identifying opportunities to reduce your tax bill
Common Tax-Loss Harvesting Mistakes
These errors can reduce or eliminate the tax benefits:
- Violating the wash-sale rule: If you buy back the same or substantially identical security within 30 days (before or after the loss sale), the loss is disallowed. This includes purchases in other accounts such as an IRA or a spouse's account
- Harvesting losses in tax-deferred accounts: Selling at a loss inside a 401(k) or IRA provides no tax benefit because gains and losses in these accounts are not recognized for tax purposes
- Letting tax savings drive poor investment decisions: Do not sell a strong long-term holding just because it has a temporary loss. The tax tail should not wag the investment dog
- Forgetting to reinvest proceeds: The goal is to stay invested. After harvesting a loss, reinvest in a similar (but not identical) fund to maintain your asset allocation and market exposure
- Not tracking cost basis carefully: Use specific lot identification to choose the highest-cost lots when selling, maximizing the loss you can harvest
Tax-loss harvesting is one of the most effective strategies for reducing taxes on investment gains. Sell losing positions to offset gains, deduct up to $3,000 of net losses against income each year, and reinvest in similar funds to maintain your portfolio allocation. Always respect the 30-day wash-sale rule and keep this strategy in taxable accounts only.
Common questions
Frequently asked questions
What is the wash-sale rule?
The wash-sale rule prevents you from claiming a tax loss if you buy the same or substantially identical security within 30 days before or after the sale. The IRS applies this rule across all your accounts (taxable, IRA, and spouse's accounts). If triggered, the disallowed loss is added to the cost basis of the replacement shares, deferring the benefit.
Can I harvest losses every year?
Yes. There is no limit on how often you can harvest losses, and unused losses carry forward indefinitely. In volatile markets, you may find opportunities to harvest losses multiple times throughout the year. Just ensure you respect the 30-day wash-sale window each time.
Does tax-loss harvesting work in a 401(k) or IRA?
No. Tax-loss harvesting only works in taxable accounts. Gains and losses inside tax-deferred (Traditional 401(k)/IRA) or tax-exempt (Roth) accounts are not recognized for tax purposes, so selling at a loss provides no tax benefit.
How much can tax-loss harvesting save me?
Savings depend on the size of your losses and your tax rate. If you harvest $10,000 in losses to offset $10,000 in long-term gains taxed at 15%, you save $1,500. If losses exceed gains, you can deduct $3,000 against ordinary income per year. At a 24% marginal rate, the $3,000 deduction saves $720 annually.
Evidence you can inspect
Sources and further reading
Use these links to check the underlying definition, rule, dataset, or consumer guidance. External pages can change after publication.