Tax-Loss Harvesting Explained: How It Works, IRS Rules, Examples & What Investors Should Know

This article is for general educational purposes only and is not individualized investment, financial, legal, or tax advice. Tax laws, investment circumstances, and individual situations vary.

If an investment loses money, selling it may sometimes provide a tax benefit. Tax-loss harvesting is an investment strategy that involves selling an investment at a loss and using that realized capital loss to potentially offset taxable capital gains.

For beginners, the important thing to understand is that tax-loss harvesting does not make an investment loss disappear. Instead, it may allow you to use that loss strategically for tax purposes while adjusting or rebalancing your portfolio.

Here is what to know about tax-loss harvesting, including how it works, the wash sale rule, capital-loss carryforwards, and common mistakes to avoid.

Tax-Loss Harvesting at a Glance

Question	Simple Answer
What is it?	Selling an investment at a loss to potentially receive a tax benefit
Where is it generally used?	Taxable investment accounts
What can losses offset?	Capital gains and, subject to limits, potentially some other income
Major rule to know	The wash sale rule
Only for year-end?	No. Opportunities can occur throughout the year
Main goal	Manage taxes without losing sight of your investment strategy

How Does Tax-Loss Harvesting Work?

Suppose you bought Investment A for $10,000 and later sold it for $14,000. You have a $4,000 capital gain.

You also bought Investment B for $8,000, but its value fell to $5,000. If you sell it, you generally realize a $3,000 capital loss.

Simplified, before considering other transactions and applicable tax rules:

The $3,000 loss may offset the $4,000 gain, leaving a $1,000 net capital gain before considering other transactions and tax rules.

This is the basic idea behind how tax-loss harvesting can reduce taxable capital gains.

Realized vs. Unrealized Losses

An investment declining in value does not necessarily mean you have a loss available to claim on your taxes.

Suppose you buy stock for $5,000 and it falls to $4,000. While you continue holding it, you generally have a $1,000 unrealized loss.

If you sell the investment for $4,000, that loss generally becomes realized.

Investors considering tax-loss harvesting therefore look at investments currently trading below their cost basis. In simple terms, cost basis is generally the amount used to determine your gain or loss when an investment is sold, subject to applicable adjustments.

Selling should not be based on taxes alone. Investors should consider what asset allocation is and why it matters and understand how to diversify investments before making changes that could unintentionally alter their portfolio.

How Tax-Loss Harvesting Works in 5 Steps

A simplified tax-loss harvesting strategy might look like this:

1. Identify an investment with an unrealized loss. Determine how much the investment has declined relative to its adjusted cost basis.
2. Decide whether selling makes investment sense. Do not sell simply to generate a tax loss.
3. Sell and realize the loss. The transaction converts an unrealized loss into a realized capital loss.
4. Consider your portfolio afterward. If you want to remain invested, carefully consider replacement investments and the wash sale rules.
5. Maintain accurate records. Investment purchases, sales, gains, losses, and cost basis can all matter at tax time.

Tax-loss harvesting may sound like a strategy only for wealthy investors, but understanding investment taxes can be valuable even when starting small. New investors may also want to consider whether to invest small amounts or wait until they have more money as they build a long-term strategy.

Short-Term vs. Long-Term Capital Gains

Capital gains and losses are generally categorized as short-term or long-term.

A short-term capital gain or loss generally results from an asset held for one year or less. A long-term capital gain or loss generally involves an asset held for more than one year.

The distinction matters because short-term and long-term capital gains can receive different federal tax treatment.

The IRS generally requires gains and losses to be netted according to specific rules, so tax-loss harvesting can be more complicated than simply subtracting every investment loss from every investment gain.

Can Capital Losses Reduce Other Income?

What happens if your eligible capital losses exceed your capital gains?

Under current federal rules, individuals may generally deduct up to $3,000 of a net capital loss against other income each year, or $1,500 if married filing separately, subject to applicable rules.

Eligible losses beyond the annual limit may generally be carried into future tax years. This is known as a capital loss carryforward.

For example, imagine you finish the year with an eligible $8,000 net capital loss and no capital gains. Subject to applicable rules, part of the loss may potentially be deductible against other income for the current year, while the remaining eligible amount may carry forward.

What Is the Wash Sale Rule in Tax-Loss Harvesting?

The wash sale rule is one of the most important tax-loss harvesting rules for beginners.

Generally, you cannot sell stock or securities at a loss, immediately repurchase the same investment, and expect to claim the loss currently for tax purposes.

A wash sale can occur when you sell stock or securities at a loss and acquire the same or substantially identical stock or securities within the period beginning 30 days before the sale and ending 30 days after it.

For example, imagine you sell shares at a $2,000 loss on November 15 and then repurchase substantially identical shares on November 25. The transaction may trigger the wash sale rules, meaning the $2,000 loss generally cannot simply be deducted currently as originally intended. Basis adjustments and other rules may apply.

Notice that purchases before the loss sale can matter too. It is not simply a rule requiring investors to wait 30 days afterward.

Because wash sales can become complicated—particularly when multiple accounts or replacement purchases are involved—investors should consider professional tax guidance before attempting more complex strategies.

Where Can You Use Tax-Loss Harvesting?

Traditional tax-loss harvesting generally applies to investments held in taxable accounts, such as individual brokerage accounts.

Tax-advantaged retirement accounts work differently. Buying and selling investments inside a traditional IRA or 401(k), for example, generally does not create currently reportable capital gains and losses in the same manner as transactions in a taxable brokerage account.

Investors learning about retirement accounts may also benefit from understanding how target-date retirement funds work and how these funds automatically adjust their investment mix over time.

When Should You Consider Tax-Loss Harvesting?

Although year-end tax-loss harvesting receives a lot of attention, investors can review potential opportunities throughout the year.

It may be worth discussing with a financial or tax professional when you have realized capital gains, an investment has fallen substantially below its cost basis, you were already considering selling an investment, or your portfolio needs rebalancing.

However, taxes should not determine whether an investment is fundamentally worthwhile.

That principle applies across asset classes. Real estate investors, for example, still need to determine whether a rental property will cash flow and estimate potential rental-property repair costs before deciding whether an investment makes financial sense.

Pros and Cons of Tax-Loss Harvesting

Most importantly, a tax benefit does not transform a poor investment into a good one.

The same principle applies when comparing investment approaches outside the stock market. Investors evaluating turnkey rentals versus fixer-uppers or strategies such as the BRRRR method of buying, renovating, renting, refinancing, and repeating should evaluate the underlying investment first and potential tax benefits second.

What Tax-Loss Harvesting Does NOT Do

Tax-loss harvesting does not erase the fact that an investment lost value. It does not guarantee that you will owe less tax, make an underperforming investment worthwhile, or mean every declining investment should be sold.

It also should not cause you to abandon your long-term investment plan solely for a short-term tax benefit.

The Bottom Line

Tax-loss harvesting involves strategically realizing qualifying investment losses that may be used to offset capital gains and potentially provide other tax benefits under applicable rules.

For beginners, the key is not to let potential tax savings dictate investment decisions. Consider cost basis, diversification, asset allocation, long-term goals, the wash sale rule, and your overall tax situation together.

Because tax laws and individual circumstances vary and can change, consider speaking with a qualified tax professional or financial advisor before selling investments primarily for tax purposes.

Frequently Asked Questions About Tax-Loss Harvesting

Is tax-loss harvesting worth it?

It can be useful for certain investors with taxable investments and capital gains, but its value depends on individual tax circumstances, portfolio goals, transaction considerations, and applicable tax rules.

Can tax-loss harvesting reduce ordinary income?

If eligible capital losses exceed capital gains, current federal rules generally allow individuals to deduct a limited net capital loss against other income, subject to applicable limits and requirements.

Can I buy the same stock back after tax-loss harvesting?

Buying the same or substantially identical stock or securities within the wash-sale window can cause the loss to be disallowed currently. The rules should be reviewed carefully before making a replacement purchase.

Can you tax-loss harvest ETFs?

Losses involving ETFs may potentially be part of a tax-loss harvesting strategy in a taxable account, but replacement investments need to be evaluated carefully for wash sale and other considerations.

Can you tax-loss harvest in an IRA or 401(k)?

Traditional tax-loss harvesting generally focuses on taxable investment accounts because gains and losses inside tax-advantaged retirement accounts are treated differently.

Is tax-loss harvesting only for the end of the year?

No. Investors may encounter tax-loss harvesting opportunities throughout the year, although year-end portfolio and tax reviews make the strategy particularly visible in November and December.