Tax-loss harvesting at $50k vs $500k income

Tax-loss harvesting is sold to everyone with a brokerage account. The pitch is identical whether you make $50,000 or $500,000. The math is not. At a $50k income, harvesting a $10,000 loss saves you about $360 this year. At $500k, the same loss saves you $3,800 or more, plus a 3.8% surcharge most people forget exists. We think TLH is wildly over-marketed to lower brackets and meaningfully under-used at higher ones, and the gap between marketing and math is where investors lose real money.

How TLH actually works

Tax-loss harvesting is selling an investment at a loss to offset gains elsewhere. The IRS lets you deduct capital losses against capital gains under Section 165. If losses exceed gains, you can deduct up to $3,000 per year against ordinary income under Section 1211(b). Anything beyond that carries forward indefinitely to future tax years.

That carryforward matters more than most articles admit. A $50,000 capital loss does not vanish. It sits on your return year after year, $3,000 at a time against ordinary income or fully against future gains, until it is used up. The tax benefit is real. The question is how much benefit, this year, at your bracket.

At $50k income: the math is small

Single filer, $50,000 in wages, no other income. For 2026, long-term capital gains rates are 0%, 15%, and 20%. The 0% bracket for single filers runs up to roughly $48,350 of taxable income for 2025, with 2026 indexing similarly upward.

After the standard deduction of roughly $15,000, this filer has about $35,000 of taxable income. They are sitting inside the 0% long-term capital gains bracket. If they harvest a $10,000 loss to offset a $10,000 long-term gain, they saved exactly $0 in capital gains tax, because they were not going to pay capital gains tax in the first place.

The only benefit at $50k income is the $3,000 ordinary income offset. At a 12% marginal federal rate, that is $360 of federal tax saved. Add a state at 5%, call it $510 total. The remaining $7,000 carries forward.

$510 in tax savings is not nothing. But it is also not the financial breakthrough the industry markets. And it comes with friction: tracking cost basis, watching wash sales, accepting tracking error from selling a position you actually wanted to hold.

At $500k income: the math is large

Same $10,000 harvested loss, single filer earning $500,000. This filer is in the 20% long-term capital gains bracket (which kicks in above roughly $533,400 in taxable income for single filers in 2025, with 2026 adjusting upward). Most of their gains face 15% federal plus the 3.8% Net Investment Income Tax under IRC Section 1411, which applies to filers above $200,000 single or $250,000 married filing jointly.

Offsetting a $10,000 long-term gain saves 15% federal + 3.8% NIIT = 18.8%, or $1,880. If the gain was short-term, taxed at the 35% ordinary rate plus 3.8% NIIT, the savings jump to $3,880. The $3,000 ordinary income offset at a 35% marginal rate saves $1,050 by itself. Stack a typical state tax of 6% and the total federal-plus-state benefit on a $10,000 harvested short-term loss can clear $4,500.

Scenario	$50k income	$500k income
LTCG rate on offset gain	0%	15% + 3.8% NIIT
Federal tax saved on $10k LTCG offset	$0	$1,880
Ordinary income offset (capped at $3k)	$3,000 @ 12% = $360	$3,000 @ 35% = $1,050
State tax saved (5% / 6% assumed)	$150	$880
Year-one total	~$510	~$3,810
Loss carried forward	$7,000	$7,000

Same trade. Same broker. Same $10,000 loss. The high earner gets roughly 7x the year-one benefit. This is why TLH belongs in every high-bracket portfolio review and is mostly noise in a low-bracket one.

The wash sale trap

The savings above evaporate if you trip the wash sale rule. Under IRC Section 1091, if you buy a substantially identical security within 30 days before or after selling at a loss, the loss is disallowed for the current year. It gets added to the cost basis of the replacement shares, which defers the benefit rather than killing it, but the current-year savings disappear.

Common ways people accidentally trigger this: dividend reinvestment in the same fund inside an IRA (the IRS has stated wash sales across taxable and IRA accounts disallow the loss permanently with no basis adjustment), buying the same ETF in a spouse's account, or selling VTI and buying ITOT thinking they are different (the IRS has never published a bright-line test for "substantially identical" for ETFs, but two funds tracking the same index with the same holdings are widely considered risky).

The safer playbook: sell one fund, buy a clearly different one tracking a different index (sell S&P 500, buy total US market, or sell large cap blend, buy large cap value). Wait 31 days before returning to your original holding if you want to swap back. Some investors stay in the substitute position permanently.

The robo-advisor TLH question

Wealthfront, Betterment, and Schwab Intelligent Portfolios all advertise automated TLH as a headline feature. They typically claim 0.5% to 2.0% in annual "tax alpha." Independent analysis is less generous. The 2019 Chambers/Heaton/Schwab study found realized benefit closer to 0.85% for early years, declining sharply over time as unrealized losses become harder to find in an appreciating portfolio.

For a $50k-income investor, even a generous 1% tax alpha on a $50,000 portfolio is $500 a year, most of which they would not capture because they are in the 0% capital gains bracket already. For a $500k-income investor with a $1,000,000 taxable account, 1% is $10,000 a year of real tax savings, every year, compounding.

Our position: if your taxable account is under $100,000 and your income is under $100,000, automated TLH is a marketing feature more than a financial one. Above $250,000 in a taxable account combined with a top-bracket income, automated TLH at a 0.25% management fee is one of the few financial products where the math reliably works out in your favor, assuming you understand the wash sale exposure across all your accounts.

The catch nobody mentions: TLH reduces your cost basis. Every harvested loss lowers what you paid (in tax terms) for the replacement shares. When you eventually sell those replacement shares, the gain is larger. TLH is a deferral, not an elimination, unless you hold until death (when basis steps up under IRC Section 1014) or donate appreciated shares to charity. For investors planning to spend the portfolio in retirement, the deferral is still valuable because it shifts tax into lower-income years. For investors planning to leave the portfolio to heirs, TLH is closer to free money.