Tax loss harvesting is worth it only if you have investment gains to offset and enough trading activity to make the strategy pay for itself

Tax loss harvesting reduces your tax bill by selling investments at a loss, then using that loss to cancel out investment gains you made elsewhere. But it only saves you money if three things are true: you have taxable gains to offset, you have enough losses available to offset them, and the tax savings exceed what you pay in trading costs and time. For most people with small portfolios or few trades, the answer is no. For people with large portfolios, frequent trading, or significant gains in a single year, the answer is often yes.

The real question is not whether the strategy works in theory — it does — but whether it works for your specific situation. That depends on your income, your investment gains, your account size, and how much you trade.

Key Takeaways

  • Tax loss harvesting only saves money if you have capital gains to offset; without gains, losses carry forward to future years and may never be used.
  • The wash-sale rule prevents you from buying the same or substantially identical investment within 30 days before or after the sale, which limits how quickly you can re-enter the market.
  • Trading costs, account fees, and the time required to track and document losses can exceed the tax savings for portfolios under roughly $100,000.
  • Tax loss harvesting works best for people in high tax brackets with large portfolios and significant gains in a single year.
  • Automated harvesting services exist, but they charge fees that may offset your tax savings unless your portfolio is large enough.

When the tax savings actually exceed the costs

The break-even point depends on your tax bracket and the size of your loss. If you are in the 24% federal tax bracket and you harvest a $10,000 loss, you save $2,400 in federal tax. If your state also taxes capital gains, you save more. But if you pay a $50 trading fee and spend two hours documenting the loss, you have already eaten into that savings.

For portfolios under $100,000, the math usually does not work. You do not generate enough losses or gains in a typical year to justify the effort. For portfolios over $500,000, especially if you are in the 32% or 37% federal bracket, the math usually works in your favor — a $50,000 loss saves you $16,000 to $18,700 in federal tax alone, which easily covers any costs.

The middle ground — portfolios between $100,000 and $500,000 — depends on how much you trade and whether you have significant gains in a given year. If you rebalance your portfolio once a year and hold most positions for years, harvesting may not be worth it. If you trade frequently or you had a very profitable year, it probably is.

The wash-sale rule and why it matters

When you sell an investment at a loss, you cannot buy the same investment or a substantially identical one within 30 days before or 30 days after the sale. If you do, the IRS disallows the loss and adds it to your cost basis in the new purchase instead. This is the wash-sale rule, and it is the biggest practical constraint on tax loss harvesting.

The rule exists to prevent people from selling a stock at a loss just to claim the deduction, then when ready buying it back. But it also means you cannot straightforward sell a losing position and buy it back the next day. You have to either stay out of that investment for 61 days, or buy a similar but not identical investment in the meantime.

For broad index funds, this is manageable — you can sell a Vanguard total stock fund and buy a Fidelity total stock fund, and the IRS will not consider them substantially identical. For individual stocks or narrowly focused funds, it is harder. You may have to hold cash or move into a different sector for a month, which means you are out of the market during that time. If the market rises, you miss the gain.

How much time and attention this actually requires

If you do this yourself, you need to track every sale, every loss, and every repurchase. You need to record the dates, the amounts, and the reason for each trade. When you file your taxes, you need to report the losses on Schedule D and reconcile them with your brokerage statements. If you make a mistake, the IRS can disallow the loss and assess penalties.

Most people underestimate how much time this takes. A single year of active harvesting can mean 10 to 20 trades, each requiring documentation. Over several years, the record-keeping becomes complex. If you sell a position at a loss, buy a replacement, then sell that replacement at a gain, you need to track the wash-sale adjustment to your cost basis. Most brokerage firms do not do this automatically.

If you use a robo-advisor or automated harvesting service, they handle the documentation for you. But they charge fees — typically 0.25% to 0.50% of assets per year. On a $100,000 portfolio, that is $250 to $500 per year. On a $500,000 portfolio, that is $1,250 to $2,500 per year. You need enough tax savings to cover that fee, or you are paying for a service that costs you money.

The scenario where it works best

Tax loss harvesting works best for people who have all of the following: a portfolio over $300,000, significant capital gains in a given year (from a bonus, a stock sale, or a very profitable investment), a high tax bracket (32% or higher), and the ability to tolerate being out of a particular investment for 30 days. If you have a $500,000 portfolio, you are in the 37% tax bracket, and you realized $100,000 in gains, harvesting losses can save you $37,000 or more in federal tax. That easily justifies the effort or the fee.

It also works well if you have a concentrated position — a single stock or fund that has grown much larger than you intended. You can harvest losses in other positions to offset the gains you will eventually realize when you sell the concentrated position. This is a common strategy for people who received company stock as compensation and want to diversify without triggering a large tax bill all at once.

When it is not worth doing

Do not harvest losses if you do not have capital gains to offset. Losses do carry forward to future years — you can use up to $3,000 of losses against ordinary income in a given year, and carry the rest forward indefinitely. But if you do not have gains now and you are not sure you will have gains later, you are just creating record-keeping work for yourself. You might harvest a loss, then never use it because you hold your investments for decades and they appreciate steadily.

Do not do it if your portfolio is small. The time and attention required do not pay off unless you have at least $100,000 to work with, and even then only if you have significant gains or losses in a given year. If you have a $50,000 portfolio and you harvest a $5,000 loss, you save maybe $1,200 in tax. That is not worth 10 hours of record-keeping.

Do not do it if you cannot tolerate being out of the market for 30 days. Some people find it stressful to hold cash or a different investment while they wait out the wash-sale period. If you are the type to panic-sell during a market dip, the emotional cost of harvesting may outweigh the tax savings.

The difference between doing it yourself and using a service

If you do it yourself, you save the fee but you pay in time and the risk of making a mistake. If you use a robo-advisor with automated harvesting, you pay a fee but you get professional documentation and you do not have to think about it. The choice depends on your portfolio size, your comfort with record-keeping, and your tax situation.

Some brokerages offer harvesting tools that are free or low-cost. Fidelity and Schwab both have tools that identify losses and suggest harvesting opportunities. If you have an account at one of these firms and you have a large portfolio, these tools can be worth using. They do not charge extra, and they handle much of the documentation for you.

If you use a full-service robo-advisor like Betterment or Wealthfront, automated harvesting is included in the fee. For portfolios over $100,000, the fee may be worth it just for the tax savings alone. For smaller portfolios, the fee is likely to exceed the benefit.

How to decide if it is right for you

Start by calculating your expected tax savings. Take your capital gains for the year, multiply by your tax bracket (federal plus state), and subtract any trading costs or service fees. If the number is positive and larger than $500, it is probably worth considering. If it is smaller than $500 or negative, it is probably not.

Next, consider your portfolio size and your trading frequency. If you have less than $100,000 or you trade less than once a year, harvesting is unlikely to be worth it. If you have more than $300,000 or you trade frequently, it probably is. In the middle, it depends on your specific gains and losses in a given year.

Finally, consider your comfort level with record-keeping and your ability to tolerate being out of a position for 30 days. If you are willing to do the work or pay for a service, and you have the portfolio size and gains to justify it, tax loss harvesting can save you real money. If not, your time is better spent on other things.

Frequently Asked Questions

Can I harvest losses in a retirement account?

No. Tax loss harvesting only works in taxable accounts. In a 401(k), IRA, or other retirement account, you do not pay tax on gains or losses, so there is nothing to harvest. The IRS does not allow you to claim losses in retirement accounts.

What if I have losses but no gains?

You can use up to $3,000 of losses against ordinary income in a given year. Any losses beyond that carry forward to future years, where you can use them against future gains or future ordinary income. But if you never have gains, the losses may never be useful. Harvesting in this case is a bet that you will have gains eventually.

Does the wash-sale rule explore if I buy a different fund in the same category?

It depends on how different the fund is. If you sell a total stock market index fund and buy a different total stock market index fund from a different company, the IRS will likely consider them substantially identical and disallow the loss. If you sell a U.S. stock fund and buy an international stock fund, they are different enough. When in doubt, ask a tax professional.

What if I make a mistake and trigger the wash-sale rule by accident?

The IRS will disallow the loss and add it to your cost basis in the new investment. This does not result in a penalty, but it does mean you lose the tax deduction. You can avoid this by tracking your purchases carefully and using a calendar to mark the 30-day window after each sale.

Is automated harvesting worth the fee?

It depends on your portfolio size and your tax bracket. For portfolios over $300,000 in the 32% or higher tax bracket, the fee usually pays for itself through tax savings. For smaller portfolios or lower tax brackets, the fee is likely to exceed the benefit. Calculate your expected tax savings and compare it to the annual fee before you sign up.