What is the wash-sale rule?

The wash-sale rule disallows a capital loss deduction when you sell a security and buy a substantially identical security within 30 days before or after the sale — a 61-day window total. To harvest a loss while maintaining investment exposure, you must replace the sold security with a similar but not identical investment. The rule applies across all your accounts, including IRA and 401(k) accounts where purchases might be triggered automatically by dividend reinvestment.

How much can I deduct from tax-loss harvesting?

Capital losses first offset capital gains dollar-for-dollar with no limit. If losses exceed gains, up to $3,000 of remaining losses can offset ordinary income per year. Any losses beyond $3,000 carry forward to future tax years indefinitely — there is no time limit on how long losses can be carried forward.

Does tax-loss harvesting make sense if I'm in a low tax bracket?

It depends. In the 0% long-term capital gains bracket, long-term losses provide less immediate benefit. However, harvesting losses that create a carryforward can be valuable if you expect higher income in future years. Short-term losses offsetting short-term gains remain valuable at nearly all income levels since short-term gains are taxed as ordinary income.

Should I coordinate my financial advisor and CPA on tax-loss harvesting?

Yes, and this coordination is where most individual investors miss harvesting opportunities. Your financial advisor controls investment decisions; your CPA understands the full tax picture including all income sources. Without coordination, you can easily create wash sales across accounts, harvest losses in suboptimal tax-year timing, or miss opportunities during market declines because no one is watching both dimensions simultaneously.

Can I harvest losses in a retirement account?

No. Losses in IRAs, 401(k)s, and other tax-deferred accounts don't generate deductible capital losses — you can't claim losses on tax-deferred account investments because gains in those accounts aren't taxed annually either. Tax-loss harvesting applies only to taxable brokerage accounts. Holdings in retirement accounts still matter for wash-sale rule compliance even though you can't harvest them.

Tax-Loss Harvesting in 2026: What It Is, How It Works, and What Your CPA Should Be Doing

August 21, 2026 · Guide · 7 min read

Tax-loss harvesting means selling investments that have declined in value to generate a capital loss, then using that loss to offset capital gains elsewhere in your portfolio — reducing your tax bill without permanently changing your investment exposure. Done correctly in 2026, it can save high-income investors $5,000 to $30,000+ annually depending on portfolio size and market conditions. Most high-net-worth individuals whose CPAs are not actively harvesting losses are leaving meaningful money on the table every year.

How Tax-Loss Harvesting Actually Works

The mechanism is straightforward: you sell an investment that has lost value, locking in a capital loss for tax purposes. That loss offsets any capital gains you have realized during the year. If your losses exceed your gains, up to $3,000 of excess loss can offset ordinary income per year, with remaining losses carried forward to future tax years indefinitely.

A Simple Example

Suppose you sell a stock holding for a $25,000 gain in 2026. Without any offsetting losses, you owe capital gains tax on the full $25,000 — at the 20% long-term rate plus 3.8% net investment income tax for high earners, that's up to $5,950. If your CPA harvests $20,000 in losses from other positions in your portfolio, you owe tax on only $5,000 — saving approximately $4,750 in this scenario.

The key insight: you don't permanently reduce your investment exposure. After selling the losing position, you reinvest in a similar but not identical investment, maintaining your market exposure while generating the tax benefit.

The Wash-Sale Rule: The Critical Constraint

The IRS wash-sale rule prevents you from selling a security at a loss and buying it back within 30 days before or after the sale — a 61-day window total. If you violate the wash-sale rule, the loss is disallowed and cannot be claimed on your taxes.

What this means in practice: when you harvest a loss in a position, you can't buy back the same security for 30 days. Instead, you buy a similar but not identical replacement. If you harvest losses in a Vanguard S&P 500 ETF, you might replace it with an iShares Core S&P 500 ETF — tracking the same index, different fund, no wash-sale issue.

The wash-sale rule applies across all accounts. If you harvest a loss in your taxable brokerage account but your IRA automatically reinvests a dividend into the same security within the wash-sale window, the loss is disallowed. This is why tax-loss harvesting requires coordination across all accounts, not just management of a single taxable account in isolation.

Common Wash-Sale Mistakes CPAs See

Selling at a loss in a taxable account while holding the same security in a 401(k) or IRA — automated reinvestment in tax-deferred accounts can trigger wash sales without the taxpayer realizing it
Buying back the original security exactly 31 days later without confirming the date falls outside the window on a calendar
Assuming similar ETFs from different providers are automatically different enough to avoid wash-sale scrutiny
Spouses holding the same security in separate accounts — the IRS applies wash-sale rules to married couples filing jointly across all accounts

Short-Term vs. Long-Term Losses: Which to Harvest First

Short-term losses (from positions held less than one year) are more valuable for harvesting than long-term losses because they offset short-term gains first — and short-term gains are taxed at your ordinary income rate (up to 37% in 2026), not the preferential 0%, 15%, or 20% long-term capital gains rate.

Your CPA should prioritize harvesting in this order:

Short-term losses to offset short-term gains (highest rate differential)
Long-term losses to offset long-term gains
Short-term losses to offset long-term gains (if no remaining short-term gains)
Long-term losses to offset short-term gains (least efficient, but still beneficial)

If you have no realized gains, harvested losses still provide value: up to $3,000 per year offsets ordinary income, and remaining losses carry forward to offset future gains. For investors expecting significant income events — business sale, RSU vesting, property sale — building a loss carryforward now can reduce taxes substantially in the year of the event.

When Tax-Loss Harvesting Makes Sense

Tax-loss harvesting is most valuable in specific circumstances:

High-income years: In the 37% ordinary income bracket or the 20% long-term capital gains bracket, the tax benefit per dollar of loss harvested is at its maximum
After market declines: A 10–20% market correction creates broad harvesting opportunities across a diversified portfolio
RSU or bonus years: Concentrated vesting events create short-term gains that losses can offset dollar for dollar
Real estate sale years: Property sales create large capital gains events where accumulated loss carryforwards become extremely valuable
Year of planned business exit: Losses harvested in previous years can offset a meaningful portion of the gain from selling a business

Conversely, harvesting is less valuable if you're in a low-income year (lower capital gains rates reduce the benefit), if you're subject to the Alternative Minimum Tax, or if you plan to pass appreciated assets through an estate (where unrealized gains may be eliminated at death through stepped-up basis).

What Your CPA Should Be Doing for You

Active tax-loss harvesting isn't something you review in April when preparing your return — it happens throughout the year, primarily when markets decline. A CPA who proactively manages your tax situation should:

Review your taxable investment accounts at least quarterly for harvesting opportunities
Coordinate with your financial advisor to ensure replacement securities are purchased immediately after harvesting, to maintain market exposure without a gap
Track wash-sale windows across all your accounts including IRAs and 401(k)s
Monitor your accumulated loss carryforwards and model when they will be most valuable to deploy
Review year-end distributions from mutual funds and ETFs, which can create unexpected gains
Model the after-tax return on harvesting versus holding — transaction costs and tracking error have real costs that reduce net benefit at smaller positions

If your current CPA only reviews your portfolio positions at tax time, you are likely missing the most valuable harvesting windows, which occur when markets are falling — not in March when everyone is preparing last year's taxes. Our guide on CPA red flags includes passive tax management as a warning sign worth evaluating in your current advisor relationship.

Tax-Loss Harvesting vs. Robo-Advisors

Several robo-advisors — Betterment, Wealthfront, Schwab Intelligent Portfolios — offer automated daily tax-loss harvesting as part of their service. For straightforward taxable accounts under $500,000 where the only complexity is standard wash-sale coordination, these automated tools can capture harvesting opportunities effectively.

However, automated harvesting doesn't coordinate across manually managed accounts, tax-deferred accounts at other institutions, or concentrated equity positions. It also doesn't model the interaction between harvested losses and your full tax picture — RSU vesting, business income, real estate gains, or the AMT. For portfolios over $500,000 or investors with multi-source income complexity, a CPA working directly with your financial advisor provides more comprehensive benefit than automation alone.

The Cost Basis Connection

When you harvest a loss and replace it with a similar investment, you reset the cost basis of the replacement position to its current lower value. When you eventually sell the replacement, you will pay capital gains tax on the full appreciation from that lower cost basis. Tax-loss harvesting defers tax — it does not eliminate it permanently.

The value comes from the time value of money (a dollar of tax paid in 10 years is worth less than a dollar paid today) and from the possibility that circumstances change before the deferred gain is realized — a lower rate in a future year, an estate step-up at death, or a charitable contribution of appreciated shares that avoids the gain entirely.

Our guide on capital gains taxes in 2026 provides context on rates and holding period rules that affect the value of harvesting specific positions. And if you're evaluating whether your current CPA is actively managing your full tax picture rather than just preparing a return, our guide on when to hire a CPA vs. tax software outlines the scenarios where proactive planning delivers the most measurable value over a passive filing-only service.

Browse CPAs by city in our directory to find tax advisors with documented investment and capital gains planning experience. Or find CPAs near you who specifically list tax-loss harvesting, investment tax planning, and portfolio tax optimization among their services — these advisors work proactively with your brokerage accounts throughout the year, not just at filing time.

Frequently Asked Questions

What is the wash-sale rule?: The wash-sale rule disallows a capital loss deduction when you sell a security and buy a substantially identical security within 30 days before or after the sale — a 61-day window total. To harvest a loss while maintaining investment exposure, you must replace the sold security with a similar but not identical investment. The rule applies across all your accounts, including IRA and 401(k) accounts where purchases might be triggered automatically by dividend reinvestment.
How much can I deduct from tax-loss harvesting?: Capital losses first offset capital gains dollar-for-dollar with no limit. If losses exceed gains, up to $3,000 of remaining losses can offset ordinary income per year. Any losses beyond $3,000 carry forward to future tax years indefinitely — there is no time limit on how long losses can be carried forward.
Does tax-loss harvesting make sense if I'm in a low tax bracket?: It depends. In the 0% long-term capital gains bracket, long-term losses provide less immediate benefit. However, harvesting losses that create a carryforward can be valuable if you expect higher income in future years. Short-term losses offsetting short-term gains remain valuable at nearly all income levels since short-term gains are taxed as ordinary income.
Should I coordinate my financial advisor and CPA on tax-loss harvesting?: Yes, and this coordination is where most individual investors miss harvesting opportunities. Your financial advisor controls investment decisions; your CPA understands the full tax picture including all income sources. Without coordination, you can easily create wash sales across accounts, harvest losses in suboptimal tax-year timing, or miss opportunities during market declines because no one is watching both dimensions simultaneously.
Can I harvest losses in a retirement account?: No. Losses in IRAs, 401(k)s, and other tax-deferred accounts don't generate deductible capital losses — you can't claim losses on tax-deferred account investments because gains in those accounts aren't taxed annually either. Tax-loss harvesting applies only to taxable brokerage accounts. Holdings in retirement accounts still matter for wash-sale rule compliance even though you can't harvest them.