If you hold a taxable brokerage account, some of your positions will spend part of the year underwater. That’s not a problem to wait out, it’s an asset most investors leave sitting on the table. Tax-loss harvesting is the practice of selling a position at a loss on purpose, using that loss to cut your tax bill, and immediately reinvesting in something similar so your portfolio keeps doing its job. Done well, it lowers what you owe without changing your market exposure. Done carelessly, it trips the wash sale rule and the benefit evaporates.
District Capital Management is a fee-only, fiduciary financial planning firm in Washington, DC, founded in 2013. We work with high-earning professionals across the DMV and nationwide, and tax-loss harvesting is one of the most underused tools we see in taxable accounts, especially among tech professionals with concentrated equity and dual-income households juggling several accounts at once. This guide covers how it works, the wash sale trap that catches most people, and when it genuinely pays off.
Key Takeaways
- Tax-loss harvesting sells a losing position to realize a capital loss, uses it to offset capital gains (no limit) or up to $3,000 of ordinary income per year, then reinvests in a similar, not identical security to stay in the market.
- The wash sale rule disallows the loss if you buy a substantially identical security within 30 days before or after the sale, in any of your accounts, including an IRA, 401(k)/TSP, or your spouse’s. Trigger it inside a retirement account and the loss is gone for good.
- It only works in taxable accounts. Losses inside an IRA, Roth IRA, 401(k), or TSP aren’t reportable and produce no tax benefit.
- The benefit is real but partly a deferral, harvesting lowers your cost basis, so it works best when your tax rate is high now and likely lower later.
What Is Tax-Loss Harvesting, and How Does It Work?
Tax-loss harvesting is selling a security in a taxable account for less than you paid, realizing the capital loss, and using it to offset capital gains or up to $3,000 of ordinary income, while reinvesting in a similar security so you stay in the market. The goal is not to exit; it’s to keep your exposure while shrinking your tax bill.
The mechanics are four steps:
- Identify a position in your taxable brokerage account worth less than you paid for it.
- Sell it and realize the capital loss.
- Immediately reinvest the proceeds in a similar, but not substantially identical security, so your allocation stays intact.
- Apply the loss: it offsets your realized capital gains first, then up to $3,000 of ordinary income; anything left over carries forward.
How Much Can You Deduct? The $3,000 Rule and the Carryforward
Harvested losses offset an unlimited amount of capital gains; if your losses exceed your gains, you can deduct up to $3,000 against ordinary income per year, $1,500 if married filing separately, and the rest carries forward indefinitely (IRS Publication 550).
Say you harvest $25,000 of losses in a year when you also have $12,000 of realized gains. The loss erases the $12,000 gain, another $3,000 comes off your ordinary income, and the remaining $10,000 carries into future years — ready to offset a future gain or shave $3,000 off ordinary income again.
For clients with sizable taxable accounts, that carryforward becomes a stored tax asset. We keep a running carryforward ledger for every client with a taxable account, so the balance gets deployed on purpose, ideally into a high-gain year like a business sale or a large RSU vest, rather than trickling away $3,000 at a time.
The Wash Sale Rule — and the Cross-Account Trap Most Investors Miss
The wash sale rule disallows your loss if you buy a substantially identical security within 30 days before or after the sale, a 61-day window in total, and, critically, it applies across all of your accounts, not just the one you sold from (IRS Publication 550). In a taxable account the disallowed loss is added to the cost basis of the replacement, so it’s deferred rather than destroyed. In a retirement account, it’s simply lost. What counts as “substantially identical”:- The same stock or fund you just sold.
- Options or contracts to buy the same security.
- A fund tracking the same index from a different provider — selling one S&P 500 ETF and buying another S&P 500 ETF is widely treated as a wash sale risk, even with a different ticker.
- Selling Vanguard Total Stock Market (VTI) and buying iShares Core S&P Total U.S. Stock Market (ITOT) — different index, similar broad exposure.
- Selling a large-cap growth ETF and buying a broad total-market ETF.
- Selling an individual stock and buying the sector ETF it belongs to.
Tax-Loss Harvesting vs. Tax-Gain Harvesting
These are mirror-image strategies: harvest losses when your bracket is high and you have gains to offset; harvest gains when your bracket is temporarily low enough to realize them at the 0% long-term rate.| Tax-Loss Harvesting | Tax-Gain Harvesting | |
|---|---|---|
| What you do | Sell positions at a loss | Sell positions at a gain |
| Primary goal | Offset gains or reduce ordinary income | Lock in gains at a lower rate; reset basis higher |
| Best used when | You have gains to offset or expect high income | You’re in the 0% long-term capital gains bracket |
| Bracket target | Higher brackets (32%+) | Low-income years (0% LTCG: ≤ $98,900 MFJ / ≤ $49,450 single, 2026) |
| Result | Immediate tax offset; a lower future basis | Higher future basis; less gain taxed later |
| Key risk | Wash sale rule | Pulling income into the current year by accident |
Tax-Loss Harvesting in Action: A Hypothetical Example
Tax-loss harvesting cuts your tax by lowering your net capital gains for the year — your realized loss is subtracted from your realized gains before the tax rate is applied. Consider Jamie, a hypothetical DC tech professional (illustrative only, not a client or an actual result). Early in the year she realized $18,000 of long-term gains. She also holds a bond fund now worth $40,000 that she bought for $55,000, a $15,000 unrealized loss. She sells the bond fund, harvests the $15,000 loss, and immediately reinvests in a similar, not identical bond fund to keep her fixed-income allocation intact.| Without harvesting | With harvesting | |
|---|---|---|
| Net capital gains | $18,000 | $3,000 ($18,000 − $15,000) |
| Long-term rate (15%; IRS, 2026) | 15% | 15% |
| Federal tax on those gains | $2,700 | $450 |
Does Tax-Loss Harvesting Actually Save Money, or Just Defer It?
Tax-loss harvesting is partly a deferral, not a pure discount; when you reinvest, your new position carries a lower cost basis, so a larger gain waits down the road. The strategy pays off when you harvest at a high rate today and eventually realize the deferred gain at a lower rate, or never realize it at all because the basis steps up to your heirs. That framing matters, because it tells you when harvesting is worth the effort and when it isn’t: If your future tax rate will be higher than today’s, harvesting can actually cost you. The benefit is largest for high-bracket investors with gains to offset. For someone in a low bracket holding broad, low-cost index funds with few gains, it’s often marginal. Thinly traded replacement funds can carry wider bid-ask spreads. Don’t let trading friction or a worse fund eat the tax saving. It adds real tracking work: cost basis, holding periods, and that 61-day window across every account. Automated “robo” harvesting can help, but it only sees the accounts it’s linked to, which is exactly where cross-account wash sales hide. Our general view: harvest deliberately, not reflexively. A loss is worth capturing when it offsets a real gain or a coming one and the replacement fund is genuinely comparable, not simply because the market dipped.When Tax-Loss Harvesting Makes the Most Sense — and When to Skip It
Tax-loss harvesting delivers the most value to investors in the 32% federal bracket or above who hold a taxable account with both unrealized losses and realized (or expected) gains in the same year. It’s worth doing when:- You have gains this year, or a large gain coming, such as a business sale, an RSU vest, a property sale, or a big rebalance.
- You’re in a high federal bracket, where each dollar of offset saves the most.
- You have carryforward losses to deploy strategically into a high-gain year.
- The position sits in a tax-advantaged account. Gains and losses inside an IRA, Roth IRA, 401(k), or TSP aren’t reportable, so selling at a loss there does nothing for your taxes. Tax-loss harvesting is a taxable-account-only strategy.
- You have no gains to offset now or soon and you’re already in a low bracket.
- You can’t find a comparable replacement without drifting from your target allocation.
Frequently Asked Questions
Tax-loss harvesting is selling an investment at a loss in a taxable account to offset capital gains, or up to $3,000 of ordinary income per year, then reinvesting in a similar, not substantially identical, security to keep your market exposure. Unused losses carry forward indefinitely (IRS Publication 550). The portfolio stays intact; the tax bill shrinks.
The wash sale rule disallows a capital loss if you buy the same or a substantially identical security within 30 days before or after the sale — a 61-day window — in any of your accounts, including retirement accounts and a spouse’s account (IRS Publication 550). In a taxable account the loss is added to the replacement’s basis; in a retirement account it’s lost permanently.
No. Gains and losses inside IRAs, Roth IRAs, 401(k)s, and the TSP aren’t reportable on your tax return, so selling at a loss there produces no tax benefit. Tax-loss harvesting only helps in a taxable brokerage account.
Partly both. Reinvesting after a harvest lowers your cost basis, so some of the gain is deferred, not erased. The net win comes from paying at a lower rate later, or never, if the basis steps up to heirs. It’s most valuable when your current bracket is high and your future bracket is likely lower.
Tax-loss harvesting sells losers to offset gains or income, best in high-bracket years. Tax-gain harvesting deliberately realizes long-term gains in a low-income year to use the 0% long-term rate (taxable income up to $98,900 MFJ or $49,450 single in 2026; IRS). Both cut lifetime taxes but work in opposite income conditions.
Yes. District Capital Management is a fee-only, fiduciary financial planning firm in Washington, DC, and tax-efficient investing, including tax-loss harvesting, wash sale compliance, and coordination with Roth conversions and income planning, is part of our investment process. Schedule a free discovery call to discuss your taxable account.
Last updated: September 2026
Alvin Carlos, CFP®, CFA is a fee-only financial planner, in Washington, D.C. He has a Master’s degree in International Relations from SAIS-Johns Hopkins. Alvin is the founder of District Capital, a financial planning firm designed to help professionals in their 30s and 40s maximize their money and retire by 55, through holistic financial planning and research-driven investing. Schedule a free discovery call today.
