Tax-Loss Harvesting: How Investors Can Turn Market Declines Into Tax Savings

A losing investment in a brokerage account is more than just clutter on the balance sheet. Two narrow sections of the tax code can let investors turn that loss into real tax savings before the year ends.

After a difficult year in the market, a brokerage account may show both lower balances and unrealized losses. That second item has actual value. By selling a losing position, investors can realize the loss and use it to offset taxable gains and reduce ordinary income. This strategy is known as tax-loss harvesting, and it is supported by two short provisions of the Internal Revenue Code.

Rising volatility tends to leave more holdings underwater, and a sale must be completed before year-end to count for the current tax year.

How a $55,000 Loss Can Save a Retired Couple $6,660

Consider a hypothetical couple, both 67, filing jointly with $150,000 of taxable income from pensions, Social Security, and traditional IRA withdrawals. Earlier in the year, they sold a winning stock and recognized a $40,000 long-term gain. They also own a fund that is worth $55,000 less than what they paid for it.

If they do nothing, the gain is taxed at the 15% long-term capital gains rate, creating a $6,000 federal tax bill. If they sell the fund before year-end, the result looks like this:

The $3,000 deduction reduces income taxed at 22% because the relevant tax bracket for married couples filing jointly reaches that rate above the lower threshold. In effect, the deduction removes the top dollars first.

Section 1211 Limits the Ordinary-Income Offset to $3,000

Under 26 U.S.C. § 1211(b), capital losses can offset capital gains without a ceiling. When losses exceed gains, individuals may deduct the smaller of $3,000, or $1,500 for married filing separately, and the excess loss. That limit is written directly into the law and is not indexed for inflation.

Any unused loss carries forward under 26 U.S.C. § 1212(b)(1), keeping its short-term or long-term character and remaining available during the taxpayer’s lifetime. In the example above, the remaining $12,000 could offset future gains or shelter $3,000 of income each year for four years. One important limitation is that an unused carryforward ends with the taxpayer and does not transfer to heirs.

Short-term losses can be especially useful. Assets held for not more than one year generate short-term gains that are taxed at ordinary rates, which can reach 37%.

The Wash-Sale Rule Can Cancel the Loss for Impatient Buyers

If you sell a losing position and buy it back too soon, the deduction is disallowed. Under 26 U.S.C. § 1091(a), a loss is not allowed if you acquire substantially identical stock or securities within the window running 30 days before and 30 days after the sale.

The loss is deferred rather than erased. Section 1091(d) adds it to the basis of the replacement shares, and Section 1223(3) carries over the holding period. The tax benefit is simply delayed.

A more serious mistake is repurchasing the same fund inside an IRA. The IRS said in Revenue Ruling 2008-5 that this creates a wash sale without any basis increase, so the loss is gone permanently. Automatic dividend reinvestment and purchases made by a spouse can also trigger the rule. A common workaround is to switch to a similar, but not substantially identical, investment for at least 31 days, such as moving from an S&P 500 fund to a total-market fund.

Wealthy Investors Harvest Year-Round, But Ordinary Investors Can Still Benefit

The wealthiest households own most of the stock market. The top 1% by wealth held 50.9% of household corporate equities and mutual funds, while the bottom half held 0.6%. Many wealthy investors use direct indexing, which involves separately managed accounts holding hundreds of individual stocks so managers can keep harvesting losses even when the broader index is rising.

Most investors can capture some of that advantage with a few basic steps:

1. Review taxable accounts first. Losses inside an IRA or 401(k) are not deductible and do not increase basis, so tax-loss harvesting only works in regular brokerage accounts.
2. Choose the right lots. Use specific-lot identification and sell the shares with the highest purchase price first.
3. Be careful in the 0% bracket. If your income is low enough that long-term gains are taxed at 0%, harvested losses may offset gains that would not have created any tax. Some investors in that situation may instead realize gains to reset their basis.

State rules are not uniform. Most states follow federal capital-loss treatment, but some do not, so it is worth checking the state return before counting on a local tax benefit.

Missed Wash Sales Can Quietly Undercut the Strategy

Harvested losses are reported on Form 8949 and Schedule D. Brokers typically flag wash sales within the same account on Form 1099-B, but they cannot see purchases made in an IRA, a spouse’s account, or another brokerage firm. Those transactions need to be tracked separately before filing.

If a large harvest affects other decisions, such as whether to do a Roth conversion, it is worth running the numbers with a CPA or a fiduciary advisor experienced in taxation.