The Hidden Costs of Tax Loss Harvesting

Tax loss harvesting is often presented as a powerful strategy to reduce investment taxes. The idea is straightforward: sell investments that have declined in value, realize a capital loss, and use that loss to offset taxable capital gains.

For investors with significant capital gains, particularly short-term gains taxed at higher ordinary income tax rates, this can be an effective tax-management strategy.

If you don't have capital gains to offset, you can generally deduct only up to $3,000 in net capital losses against ordinary income annually, or $1,500 if married filing separately, with unused losses carried forward to future years.

Beyond these limitations, there are several less obvious costs and risks that investors should understand before implementing tax loss harvesting.

1. Wash Sale Rules Apply Across Accounts, Including Your Spouse's Accounts

The IRS wash sale rule is one of the most important restrictions on tax loss harvesting.

Generally, a wash sale occurs when you sell a security at a loss and purchase the same or a substantially identical security within 30 days before or after the sale.

That creates a 61-day window surrounding the transaction, including the sale date.

What many investors overlook is that wash sale rules are not limited to a single brokerage account.

They can apply across:

• Multiple taxable brokerage accounts you own.
• Your spouse's investment accounts.
• Traditional and Roth IRA accounts.
• Purchases made through automatic dividend reinvestment.
• Certain options and other transactions involving substantially identical securities.

For example, suppose you sell 100 shares of a stock in your taxable brokerage account at a $5,000 loss.

Ten days later, your spouse purchases 100 shares of the same stock in a separate brokerage account.

Illustrative example assuming all 100 replacement shares are substantially identical and the full $5,000 loss is subject to the wash sale rule.

Even though the purchase occurred in a different account and was made by your spouse, the wash sale rules can disallow the loss.

For an ordinary taxable-account wash sale, the disallowed loss is generally added to the replacement securities' cost basis, deferring the deduction rather than permanently eliminating it.

However, wash sales involving purchases inside an IRA or Roth IRA are particularly costly. If you sell shares at a loss in a taxable account and acquire substantially identical shares in an IRA during the wash sale window, the loss can be permanently disallowed rather than preserved through a basis adjustment.

Brokerage firms may not identify every wash sale occurring across different accounts or between spouses. Coordinating transactions and maintaining accurate records is ultimately the taxpayer's responsibility.

2. Tax Loss Harvesting Can Interfere With Automated Dividend Reinvestment

Many investors use dividend reinvestment plans, commonly called DRIPs, to automatically purchase additional shares whenever an investment pays a dividend.

However, automated dividend reinvestment can create an unexpected problem when combined with tax loss harvesting.

Imagine you sell shares of an ETF to realize a $10,000 capital loss.

Two weeks later, the same ETF pays a dividend in another account, and your automatic dividend reinvestment plan purchases additional shares.

That purchase could trigger a wash sale, even if you never manually placed a buy order.

Illustrative example assuming an equal $100 loss per share, no other wash sale transactions, and a $500 dividend reinvestment purchasing five substantially identical shares.

The wash sale adjustment generally applies to the number of replacement shares purchased. A small dividend reinvestment may therefore disallow only a portion of the harvested loss, rather than the entire $10,000.

To avoid this problem, investors may need to temporarily disable dividend reinvestment for affected securities across accounts and coordinate purchases with their spouses.

A strategy designed to automate tax savings can end up disrupting other automation that investors already rely on.

3. Frequent Harvesting Can Reduce the Tax Benefits of Qualified Dividends

Qualified dividends generally receive preferential federal tax rates of 0%, 15%, or 20%, depending on taxable income. Nonqualified dividends are generally taxed at ordinary income tax rates.

To qualify for preferential tax treatment on common-stock dividends, investors generally must hold the shares for more than 60 days during the 121-day period beginning 60 days before the ex-dividend date.

Frequent tax loss harvesting can interfere with this requirement.

For example, imagine an investor purchases a dividend-paying ETF, receives a dividend shortly afterward, and sells the ETF at a loss before meeting the required holding period.

Even if the dividend would otherwise have qualified for preferential treatment, it may become taxable at ordinary income tax rates because the holding-period requirement was not satisfied.

Consider $5,000 in dividends that would otherwise qualify for a 20% federal tax rate.

Illustrative example, excluding the net investment income tax and state income taxes.

In this example, the investor could incur an additional $850 in federal taxes by losing qualified dividend treatment.

The qualified dividend holding period is separate from the wash sale holding period, so avoiding wash sales alone does not solve this problem.

For investors using frequent automated tax loss harvesting, especially with dividend-paying investments, these additional taxes can reduce the overall benefit of the strategy.

4. Sitting Out of the Market Can Cause Investors to Miss a Rebound

One way to avoid wash sale violations is to sell an investment and wait more than 30 days before repurchasing it.

However, remaining in cash during that period introduces market timing risk.

Suppose you sell $100,000 of an ETF after a market decline to harvest a capital loss.

You decide to wait 31 days before purchasing the same ETF again.

During those 31 days, the market rebounds by 8%.

Your investment would now be worth $108,000 had you remained invested.

Illustrative example assuming no return on cash and excluding transaction costs.

By holding cash, you missed $8,000 of market appreciation, before considering any return earned on the cash.

The missed gain could easily exceed the tax benefit you expected from harvesting the loss.

This is why investors generally try to maintain market exposure during the wash sale window rather than remaining entirely in cash.

But doing so introduces another tradeoff: replacement investments may not deliver identical returns.

5. Similar Replacement Investments Do Not Always Deliver Identical Returns

To avoid wash sale issues while staying invested, investors often replace a sold security with another investment that has similar market exposure but is not substantially identical.

For example, an investor might sell an ETF tracking one broad U.S. stock market index and purchase an ETF tracking a different broad U.S. stock market index.

Although both investments may provide similar exposure, their returns will not necessarily be identical.

Differences can arise from index construction, company weightings, sector exposure, fund expenses, and dividend distributions.

Consider a simple example:

The replacement ETF underperformed the original by $800.

The tracking difference can also work in the investor's favor. A replacement investment might outperform the original.

But the important point is that similar investments are not interchangeable in terms of actual returns.

Investors who repeatedly switch between replacement securities may accumulate tracking differences over time.

There is also uncertainty around which funds are considered substantially identical for wash sale purposes. Choosing a different ETF ticker does not automatically establish that a transaction avoids the wash sale rules.

6. Selling Replacement Investments Too Soon Can Create Higher Short-Term Capital Gains

After harvesting a loss, investors typically purchase a replacement investment to maintain market exposure.

But that purchase can create a new holding-period consideration.

Imagine you purchased an investment for $100,000, and its value declined to $80,000.

You sell the investment, realizing a $20,000 capital loss, and purchase a different, non-substantially-identical investment for $80,000.

Six months later, the replacement investment recovers to $100,000.

If you sell it at that point, the $20,000 gain will generally be short-term because you held the replacement for less than one year.

For a high-income investor, the gain could be taxed at a federal rate of 37% rather than the preferential 20% long-term capital gains rate.

The potential tax difference is $3,400.

This does not necessarily mean harvesting the original loss was a mistake. The original loss may have offset other taxable gains, and the overall result depends on both transactions.

The overall tax benefit depends on how the original harvested loss was used, the tax rates applicable to those gains, and the taxes eventually paid when selling the replacement investment.

The tax benefit of harvesting a loss today must be evaluated alongside the potential tax consequences of selling the replacement investment later.

This example assumes no wash sale occurred. In an ordinary taxable-account wash sale, the replacement shares can inherit the original holding period, changing the analysis.

Final Thoughts

Tax loss harvesting can be an effective strategy for investors with significant capital gains, particularly short-term gains taxed at higher rates.

However, the benefits need to be weighed against wash sale restrictions, additional taxes, portfolio tracking differences, and the risk of missing market rebounds. Investors should also consider the future tax consequences of holding replacement investments with a lower cost basis.

Remember that tax loss harvesting applies to taxable investment accounts. Losses realized inside retirement accounts generally do not provide deductible capital losses.

Ultimately, the goal should not be to maximize harvested losses, but to maximize long-term after-tax investment returns.

References

• IRS Publication 550: Investment Income and Expenses
• IRS Publication 544: Sales and Other Dispositions of Assets
• IRS Topic 409: Capital Gains and Losses