TL;DR Answer Box

Tax loss harvesting is the strategy of selling investments at a loss in a taxable account to offset capital gains and potentially reduce taxes. For high earners, the biggest value is usually offsetting realized gains, not the $3,000 ordinary income deduction. The strategy works best when you avoid wash sales, keep your portfolio exposure intentional, and understand the cost basis trade off. Last updated: February 18, 2026.

Introduction

Tax loss harvesting sounds like something you would only do with a CPA, a candlelit office, and a 97-tab spreadsheet.

In practice, it is a straightforward tool that can reduce taxes and improve portfolio efficiency when markets get messy. It is not “free money.” A loss is still a loss. But if you already have losses, you can often put them to work instead of letting them sit there doing nothing.

If you are a tech professional, you are more likely to have the ingredients that make tax loss harvesting matter. Equity compensation, concentrated positions, and large swings in income can make the timing of gains and losses a real planning lever.

What tax loss harvesting is

Tax loss harvesting is the act of selling an investment for less than you paid for it, so the realized loss can be used to offset realized gains and potentially reduce taxes.

The key word is realized. A loss on paper does not help you until you sell.

The two outcomes you are trying to create

• Outcome 1: Offset capital gains dollar-for-dollar. If you realized gains this year, losses can often reduce how much of those gains are taxable.
• Outcome 2: Build a “loss bank” you can carry forward. If you do not have enough gains this year to use all the losses, you may be able to carry the remaining losses into future years.

If you want a quick primer on how capital gains work, including holding period and cost basis, start here: What are Capital Gains?.

The $3,000 ordinary income limit

You will often hear one headline stat: the IRS generally allows up to $3,000 of net capital losses to reduce ordinary income per year (with a lower limit in some filing situations). That matters, but it is rarely the main event for high earners.

Here is the better mental model: for high earners, tax loss harvesting usually matters most when it offsets capital gains, especially in years where you are already stacking income from salary, bonus, RSUs, or a liquidity event.

How tax loss harvesting works in real life

The goal is not to “trade more.” The goal is to improve your after-tax outcome while keeping your portfolio aligned with your plan.

Step-by-step workflow

1. Identify losses that matter: Look for positions with meaningful unrealized losses, especially positions you would not mind replacing or repositioning.
2. Check your holding period and gain picture: Harvesting is most powerful when you have realized gains to offset, or when you want to build carryforwards for a future gain year.
3. Disable automatic reinvestments: Turn off dividend reinvestment and automated purchase plans on the security you are harvesting. Automatic buys can accidentally create wash sales.
4. Sell the loss position: This is what makes the loss real for tax purposes.
5. Choose a replacement plan immediately: Either buy a different fund that keeps similar exposure without being “substantially identical,” or hold cash and wait 31 days before repurchasing the original position.
6. Document what you did: Keep notes on the trade date, replacement purchase, and why you chose the replacement. Clean documentation helps you and your tax team later.

For a deeper strategy walkthrough and examples, see Harvesting Tax Losses to Beat Capital Gains.

The wash sale rule

The wash sale rule is where most “simple” tax loss harvesting mistakes happen.

In plain English, the rule generally prevents you from claiming a loss if you sell a security at a loss and then buy the same or “substantially identical” security within 30 days before or after the sale.

Two practical implications matter most:

• It is not just your main brokerage account: Wash sales can be triggered by purchases across accounts you control, including automated reinvestments.
• It is not just manual trades: Dividend reinvestments and recurring purchases can trigger wash sales quietly in the background.

The IRS has not always provided investor-friendly clarity on what “substantially identical” means in every scenario, which is why many high earners use a replacement fund that maintains similar exposure but tracks a different index or uses a different strategy.

This is also why coordination matters. If you are harvesting meaningful dollars, it is worth having your advisor and CPA aligned on the plan.

The cost basis trade off

Here is the part that separates “doing tax loss harvesting” from doing it well.

If you sell a position at a loss and later buy it back at a lower price, your new purchase price becomes your new cost basis.

That can be great in the short run because you created a loss that may reduce taxes. It can also mean higher taxable gains later if the investment recovers and you sell in the future, because the gain is measured from that new, lower cost basis.

Tax loss harvesting is often a timing strategy. You are trading a benefit today for a different tax picture later. Sometimes that is a clear win. Sometimes it is neutral. Sometimes it is not worth the complexity.

Case study

Let’s make this tangible with your example structure, cleaned up and decision-focused.

Zach’s $20,000 loss bank

Zach has $20,000 in unrealized losses across a few investments from the last three years.

Move 1: Offset capital gains

• If Zach realizes $10,000 of capital gains this year, he can generally use $10,000 of losses to offset those gains dollar-for-dollar.
• Result: his net taxable capital gains may be reduced, potentially to zero, depending on the rest of his situation.

Move 2: Deduct a portion against ordinary income

• After offsetting gains, if Zach still has remaining net losses, he may be able to deduct up to $3,000 against ordinary income this year (subject to eligibility and filing status).
• If Zach is in a 30% marginal bracket, a $3,000 reduction in ordinary income could reduce tax by about $900. The loss still happened, but the tax impact is softened.

Move 3: Carry forward the rest

• If Zach started with $20,000 of losses and used $10,000 to offset gains plus $3,000 against ordinary income, he has $7,000 remaining.
• He may be able to carry those losses forward into future years, using them to offset future gains and potentially deducting up to the annual ordinary income limit each year until used up.

Simple comparison “table”

• Best use case: You have realized gains this year (or expect a future liquidity event) and want to reduce the tax impact without changing your long-term plan.
• Main win for high earners: Offsetting capital gains. The $3,000 ordinary income deduction is usually secondary.
• Main risk: Wash sales, especially from automated reinvestments or uncoordinated buying.
• Main trade off: A new, lower cost basis can increase future taxable gains if you later sell after a rebound.

What this means for high earners

If you are a high earner, taxes are often your largest controllable expense. Tax loss harvesting is one lever, but it should be connected to the rest of your system.

Here are a few scenarios where it can matter more than people expect:

• Equity compensation years: RSU income can push you into higher brackets, and selling stock can layer capital gains on top.
• Liquidity events: IPOs and acquisitions can create large one-time gains. A carryforward loss bank can become very valuable in those years.
• Concentrated positions: Harvesting can be a clean way to reposition out of risk, as long as the replacement strategy keeps exposure aligned.

If you want a practical guide specifically for down markets and harvesting opportunities, read Down Market Tactics: A Modern Investor’s Guide to Tax Loss Harvesting.

If you are consistently generating investment income and gains at higher income levels, NIIT may also be part of your planning picture. This guide can help you connect those dots: A Comprehensive Guide to NIIT for High-Income Earners.

Common mistakes

• Only thinking about harvesting in December: the market does not wait for year-end. Harvesting is often more effective when it is opportunistic and planned.
• Triggering wash sales unintentionally: dividend reinvestment and recurring purchases are the usual culprits.
• Harvesting into cash with no plan: sitting in cash for 31 days can create opportunity cost if markets rebound quickly.
• Chasing the tax benefit while breaking your allocation: you can “win” a tax trade and still lose by drifting into the wrong portfolio exposure.
• Ignoring the cost basis reset: harvesting can create future taxes if you later sell from a lower basis.

Action steps

1. Run a quarterly loss scan: review unrealized losses and your realized gain picture at least quarterly, not only in December.
2. Turn off automatic reinvestment on candidates: do this before selling to reduce wash sale risk.
3. Define the purpose: offset gains this year, build carryforwards for a future gain year, rebalance away from concentration, or a combination.
4. Choose a replacement strategy: either a non-identical fund that maintains exposure or a deliberate 31-day wait with a clear reinvestment plan.
5. Track cost basis and holding periods: if you harvest frequently, documentation stops small errors from compounding into big ones.
6. Coordinate with your tax team: when the numbers get meaningful, make sure your CPA and advisor are aligned on execution and reporting.

Key Takeaways

• Tax loss harvesting turns realized investment losses into potential tax benefits.
• For high earners, the main value is usually offsetting realized capital gains.
• The $3,000 ordinary income deduction is real, but often not the primary driver.
• Avoiding wash sales is a core part of doing this correctly.
• Harvesting can reset cost basis lower, which can increase future taxable gains if you later sell after a rebound.
• Done well, harvesting supports a broader plan. Done randomly, it creates complexity without a clear payoff.

Facts/FAQ

Is tax loss harvesting only a December strategy?

No. Many investors focus on year-end, but tax loss harvesting can be evaluated throughout the year. A quarterly review is often more practical for high earners because gains and losses can change quickly with markets and equity compensation activity.

Can I tax loss harvest inside a 401(k) or IRA?

Generally, no. Tax loss harvesting is a taxable account strategy. Retirement accounts like 401(k)s and IRAs are tax-advantaged accounts, and realized gains or losses inside them typically do not flow through to your current tax return in the same way.

How does the wash sale rule work in plain English?

If you sell an investment at a loss and buy the same or substantially identical investment too close to that sale date, the IRS may disallow the loss for current tax purposes. Wash sales can be triggered by automated reinvestments, which is why turning off reinvestment is often step one.

What does “substantially identical” mean?

The IRS does not always define this in a way investors find intuitive across every scenario. A practical approach many investors use is replacing a position with a similar, but not identical, fund to maintain exposure while reducing wash sale risk. Specific facts matter, so confirm your approach with your tax advisor.

What is the $3,000 capital loss limit and why do high earners still care?

Taxpayers may be able to deduct up to $3,000 of net capital losses against ordinary income each year (subject to filing status rules). High earners still care because unused losses may carry forward, and in gain-heavy years, losses can offset capital gains dollar-for-dollar, which is often the bigger benefit.

Does tax loss harvesting increase future taxes?

It can. If you sell at a loss and later repurchase at a lower price, your new cost basis may be lower. If the investment rebounds and you later sell, the taxable gain could be larger. The decision is about whether today’s tax benefit outweighs the future trade off.

Internal Links

• Harvesting Tax Losses to Beat Capital Gains: Deeper strategy breakdown and supporting examples.
• What are Capital Gains?: Cost basis and holding period context that makes harvesting decisions clearer.
• Down Market Tactics: A Modern Investor’s Guide to Tax Loss Harvesting: How to harvest in down markets without breaking your plan.
• A Comprehensive Guide to NIIT for High-Income Earners: Additional tax layer that can matter when gains are large.

External Links

• Fidelity: Capital gains tax rates overview

CTA

Tax loss harvesting is simple. Doing it correctly inside a real plan is where high earners win.

If you want to connect tax loss harvesting to your full system (equity compensation, concentrated stock, cash needs, and multi-year tax planning), schedule a complimentary Financial Analysis: https://go.oncehub.com/FreeFinancialAnalysis.

You will walk away with clarity on what to harvest, what to hold, how to avoid wash sales, and how to keep your portfolio aligned while improving after-tax outcomes.

Disclaimer

This material is for general information only and is not intended to provide specific investment, tax, or legal advice. Rules and eligibility depend on your facts and may change. Consult your CPA and financial professional before acting.