Tax-Loss Harvesting: A Complete Guide to Lowering Your Tax Bill

Tax-loss harvesting is one of the most powerful tools for reducing taxes on investments. Done right, it can save thousands annually while keeping your portfolio on track.

What Is Tax-Loss Harvesting?

Tax-loss harvesting involves selling investments at a loss to offset capital gains elsewhere in your portfolio. The "harvested" losses reduce your taxable income, lowering your tax bill.

Simple Example:

• You sold Stock A for $10,000 gain

• You sell Stock B at $8,000 loss

• Net taxable gain: $2,000 (instead of $10,000)

• Tax savings: $1,600+ depending on bracket

How Tax-Loss Harvesting Works

Step 1: Identify Losing Positions

Review your taxable investment accounts for positions below your purchase price:

• Individual stocks down

• ETFs below cost basis

• Mutual funds with losses

Step 2: Sell the Losing Investment

Execute the sale to realize the loss:

• Transaction creates "realized" loss

• Loss can now offset gains

Step 3: Buy a Similar (Not Identical) Investment

To maintain portfolio allocation, buy a similar investment:

• If selling S&P 500 ETF (VOO), buy total market ETF (VTI)

• If selling growth fund, buy different growth fund

• Maintains market exposure

Step 4: Wait 30 Days (Wash Sale Rule)

After 30 days, you may:

• Repurchase the original investment

• Or keep the replacement investment

The Wash Sale Rule

The IRS prevents you from claiming a loss if you buy "substantially identical" securities within 30 days before or after the sale.

What Triggers a Wash Sale:

• Buying same stock within 61-day window (30 before + sale day + 30 after)

• Buying substantially identical mutual fund

• Spouse buying same security

• IRA buying same security

• Dividend reinvestment buying same security

What Doesn't Trigger Wash Sale:

• Different index tracking same market (VOO vs. VTI)

• Different company in same sector

• Stock vs. bond of same company

Wash Sale Consequences:

If triggered:

• Loss is disallowed

• Loss added to new purchase's cost basis

• Not permanent loss—just deferred

Tax-Loss Harvesting Limits

Offsetting Capital Gains

Losses first offset gains of the same type: 1. Short-term losses → Short-term gains 2. Long-term losses → Long-term gains 3. Remaining losses offset opposite type

Annual Loss Deduction

If losses exceed gains:

• Deduct up to $3,000 against ordinary income

• Carry forward remaining losses indefinitely

• Use $3,000 each year until exhausted

Example:

• Capital gains: $2,000

• Capital losses: $15,000

• Net loss: $13,000

• Year 1 deduction: $3,000

• Carryforward: $10,000

• Year 2 deduction: $3,000

• And so on...

When to Tax-Loss Harvest

Best Times:

Market Downturns:

• More losing positions available

• Opportunities to harvest without selling winners

Year-End:

• Know your full-year gains

• Last chance before tax year closes

• December is common harvesting month

After Large Gains:

• Selling a house

• Selling concentrated stock position

• Receiving bonus in company stock

Avoid Harvesting When:

• No capital gains to offset (and $3,000 limit reached)

• Position will trigger wash sale

• Transaction costs outweigh tax benefit

• You believe investment will rebound significantly soon

Tax-Loss Harvesting Strategies

Basic Strategy

Harvest losses year-end to offset that year's gains: 1. Review portfolio in November/December 2. Identify losses 3. Calculate gains 4. Harvest enough to offset gains 5. Reinvest in similar securities

Continuous Harvesting

Monitor and harvest throughout the year:

• Check monthly for harvesting opportunities

• Maximize opportunities in volatile markets

• Robo-advisors do this automatically

Direct Indexing

For portfolios $100k+:

• Own individual stocks instead of ETF

• Harvest losses in individual positions

• More opportunities than owning ETF

• Wealthfront offers this at $100k

Tax-Loss Harvesting Examples

Example 1: Simple Offset

Portfolio:

• Sold Stock A: $15,000 gain (long-term)

• Holding Stock B: $8,000 loss

Action:

• Sell Stock B to realize $8,000 loss

• Buy similar investment

• Net taxable gain: $7,000 (instead of $15,000)

• Tax savings: ~$1,500 (at 20% rate)

Example 2: Loss Exceeds Gains

Portfolio:

• Capital gains: $5,000

• Harvested losses: $20,000

Result:

• Offset all $5,000 gains

• Remaining loss: $15,000

• Deduct $3,000 from ordinary income

• Carryforward: $12,000 to future years

Example 3: Wash Sale Avoidance

Original: Own Vanguard S&P 500 ETF (VOO) Loss: $10,000

Wrong approach:

• Sell VOO

• Buy VOO within 30 days

• Loss disallowed

Correct approach:

• Sell VOO

• Buy Schwab S&P 500 ETF (SWPPX) or VTI

• After 31 days, can switch back to VOO

Automated Tax-Loss Harvesting

Wealthfront

• Daily tax-loss harvesting

• Claims to add 1.8%+ annually

• Direct indexing at $100k

• Automatic wash sale prevention

Betterment

• Tax-loss harvesting included

• Tax-coordinated portfolios

• Automatic rebalancing

• Wash sale monitoring

M1 Finance

• Tax minimization features

• Automatic tax-efficient selling

• Free service

Tax-Loss Harvesting Best Practices

Do:

1. Document everything: Keep records of all transactions 2. Consider state taxes: Some states don't allow loss deductions 3. Mind transaction costs: Ensure tax savings exceed costs 4. Use tax-efficient replacements: Choose similar but not identical funds 5. Review wash sale exposure: Check all accounts including IRAs

Don't:

1. Let taxes drive all decisions: Don't sell just for the loss if you believe in investment 2. Ignore wash sales: IRS computers catch these 3. Forget about carryforwards: Track and use them 4. Harvest in retirement accounts: No taxable gains to offset 5. Assume losses are bad: They're opportunities for tax savings

Tax-Loss Harvesting Limitations

When It Doesn't Work:

• Retirement accounts: No taxes on gains inside IRA/401k

• Low tax brackets: Benefits reduced

• No gains: Limited to $3,000/year deduction

• Short holding periods: May create short-term gains later

Potential Downsides:

• Lower cost basis: Future gains may be higher

• Transaction costs: Trading fees add up

• Complexity: Requires tracking and planning

• Wash sale traps: Easy to accidentally trigger

Tools for Tax-Loss Harvesting

Investment Growth Calculator

Model how tax savings compound over time

Net Worth Calculator

Track overall wealth including tax benefits

Brokerage Tax Reports

Year-end summaries show gains and losses

Your Tax-Loss Harvesting Plan

Monthly:

• Review positions for losses

• Check if gains exist to offset

• Execute harvests as opportunities arise

Quarterly:

• Assess YTD gains and losses

• Plan harvesting strategy

• Review wash sale exposure

Annually:

• November/December comprehensive review

• Final harvest opportunities

• Document all transactions

Related Resources

• Wealthfront Review - Automated harvesting

• Robo-Advisors Explained

• Investment Growth Calculator

• Tax Planning Strategies

Conclusion

Tax-loss harvesting is free money from the IRS. While it requires attention and planning, the potential to save thousands annually makes it worthwhile for any taxable investment portfolio.

Whether you do it manually or use a robo-advisor, make tax-loss harvesting part of your investment strategy. Your future self (with a lower tax bill) will thank you.