Tax Loss Harvesting: A Guide for High-Earning Women
TLDR
Tax loss harvesting — selling positions at a loss to offset capital gains — is most valuable for high earners with significant taxable investment activity, RSU sales, or large equity comp vesting events. The wash sale rule limits the strategy but doesn't eliminate it. At the 20% long-term capital gains rate plus 3.8% net investment income tax, the math on harvesting losses is particularly favorable.
- Tax Loss Harvesting
- Selling a security at a loss to realize that loss for tax purposes, then immediately replacing it with a similar (but not identical) investment to maintain market exposure. The realized loss offsets capital gains, reducing your tax bill. Losses above capital gains can offset up to $3,000 of ordinary income annually, with excess carried forward indefinitely.
DEFINITION
- Wash Sale Rule
- IRS rule that disallows a loss deduction if you purchase a 'substantially identical' security within 30 days before or after the sale. You can avoid the wash sale by purchasing a different but similar fund — selling S&P 500 fund A and buying S&P 500 fund B is usually acceptable; selling a stock and buying the same stock within 30 days is not.
DEFINITION
- Net Investment Income Tax (NIIT)
- An additional 3.8% tax on investment income for high earners — single filers with MAGI above $200,000, joint filers above $250,000. Applied to capital gains, dividends, interest, and passive income. Means high earners effectively pay 23.8% on long-term capital gains (20% + 3.8%), making tax loss harvesting more valuable.
DEFINITION
Why Tax Loss Harvesting Matters More at High Income
Tax loss harvesting — selling losing positions to realize losses that offset capital gains — is a strategy available to any investor with a taxable account. But its value is directly proportional to your tax rate on capital gains.
For high earners:
- Long-term capital gains rate: 20% (for single filers above ~$518,000)
- Net Investment Income Tax: 3.8% on investment income above MAGI thresholds
- Combined rate on long-term gains: 23.8%
- Short-term capital gains: taxed as ordinary income (up to 37%)
A $100,000 loss harvested against long-term gains saves approximately $23,800. Against short-term gains (which you have from RSU lots held under 12 months), the savings are even higher.
The math makes harvesting significantly more valuable for high earners than for people in lower tax brackets.
How It Works
The mechanics are simple:
- You own a fund or stock that’s down from your cost basis
- You sell the position, realizing a capital loss
- You immediately reinvest in a similar (but not identical) investment to maintain market exposure
- The realized loss offsets capital gains in your portfolio (or up to $3,000 of ordinary income, with excess carried forward)
The key constraint is maintaining market exposure. Selling a losing position and moving to cash would work for tax purposes, but you’d lose the investment return during the 30-day window. The strategy preserves returns while capturing the tax benefit.
The Wash Sale Rule in Practice
The IRS prevents a simple tax gaming strategy: sell at a loss, immediately rebuy, claim the loss. The wash sale rule disallows the loss if you purchase a “substantially identical” security within 30 days before or after the sale.
“Substantially identical” is interpreted strictly for single stocks (don’t rebuy the same stock within 30 days) but more loosely for funds — different funds tracking similar indexes are generally considered non-identical even if they have very similar returns.
Common acceptable substitutions:
- Vanguard S&P 500 ETF (VOO) → iShares S&P 500 ETF (IVV)
- Vanguard Total Market (VTI) → Schwab Total Market (SCHB)
- Individual stock in a sector → sector ETF (may or may not qualify as “substantially identical” depending on circumstances)
After 30 days, you can repurchase the original fund if you prefer it.
When to Harvest
During market downturns. When the market is down 10-15%, many positions in a diversified portfolio will be below cost basis. This is the prime harvesting window.
After RSU vests. If you’ve been holding RSU shares and some lots are now below their vest price (due to market movement after vesting), those are harvestable losses that can offset gains from appreciated lots.
End of year. Calendar year tax planning often triggers a review of taxable accounts for harvesting opportunities before December 31.
When rebalancing. If you’re selling overweight positions to rebalance, check whether you have offsetting losses available to reduce the tax impact.
Harvesting at Scale: Automated vs. Manual
Robo-advisors with automated tax loss harvesting (Betterment, Wealthfront, Schwab Intelligent Portfolios) monitor your taxable portfolio daily and execute harvests automatically when thresholds are met. For a purely managed taxable account, this can add meaningful annual value without ongoing attention.
For active investors managing their own portfolios, manual harvesting is an annual or opportunistic exercise. The limitation is attention — it’s easy to miss harvesting windows if you’re not watching the portfolio actively.
For high earners with significant annual RSU income creating capital gains exposure, the combination of automated harvesting in managed accounts plus manual review during RSU vesting periods is the most complete approach.
Q&A
How much is tax loss harvesting worth for a high earner?
At the 20% long-term capital gains rate plus 3.8% NIIT, a $50,000 harvested loss saves approximately $11,900 in taxes (23.8% × $50,000). Against short-term capital gains or ordinary income (capped at $3,000/year), the rate is higher. The value depends on how many gains you have to offset — the harvest is most valuable when you have large capital gains to offset in the same tax year.
Q&A
Does tax loss harvesting apply to RSU sales?
RSU shares vesting create ordinary income, but gains or losses after vesting are capital gains/losses. If RSU shares vest at $80 and you sell at $70, you have a $10/share short-term capital loss (assuming you sell within a year of vesting). These losses can offset other capital gains. If you sold other RSU lots that appreciated, harvesting losses on underwater positions reduces the net tax.
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