Tax-loss harvesting is real but badly oversold: banking a capital loss usually does not eliminate tax, it only delays it, because your cost basis drops by the amount you harvested. The benefit is genuine in three cases — when the loss offsets short-term gains taxed at ordinary rates, when the deferral runs for decades, and when the position gets a step-up in basis at death. Outside those, the “tax alpha” in marketing material rarely shows up on a real retiree’s return.
From the Retirement Tax Planning hub — Evergreen Wealth Management — proactive year-round tax planning for retirees: Roth conversions, withdrawal sequencing, and Medicare IRMAA strategy.
What is tax-loss harvesting, exactly?
It is selling an investment worth less than you paid, realizing the loss on purpose, and immediately buying something similar so you stay invested.
Under the IRS rules on capital gains and losses, that realized loss does three things in order: it offsets capital gains of the same type, then gains of the other type, then up to $3,000 of ordinary income per year. Anything left carries forward indefinitely.
One thing gets skipped: harvesting only works in a taxable brokerage account. There is nothing to harvest inside an IRA, 401(k), or Roth. If most of your money sits in retirement accounts — true for many Boston households I work with — the strategy covers a far smaller slice of your net worth than the pitch implies.
Why isn’t tax-loss harvesting free money?
Because when you sell at a loss and buy a replacement, your new cost basis is the lower price. You have not erased a gain — you have moved it into the future.
You bought a fund for $100,000; it is now worth $70,000. You sell, harvest the $30,000 loss, and buy a similar fund. If it climbs back to $100,000 and you sell, you owe tax on a $30,000 gain that would not have existed had you simply held. The loss you claimed and the gain you later recognize are the same $30,000.
The honest description: an interest-free loan from the IRS, sized to the tax you deferred, for as long as you hold the replacement. Worth something — not worth what the marketing suggests.
How much is tax-loss harvesting actually worth?
It depends almost entirely on the gap between the rate the loss offsets today and the rate you pay when the gain returns. Same rate and a short holding period means a small benefit; a big rate gap or a long deferral means a real one.
Here is $60,000 of harvested losses across three situations, using 2026 federal rates, the 3.8% net investment income tax where it applies, and the Massachusetts 5% flat rate.
| Situation | Tax saved now | Tax owed later | Real net benefit |
|---|---|---|---|
| Retired couple, $90,000 taxable income, already in the 0% long-term capital gains bracket | ~$510/year (12% federal + 5% MA on $3,000 of ordinary income) | Future gains likely taxed at 0–15% | Near zero. Takes 20 years to use the carryforward |
| Pre-retiree in the 24% bracket, unwinding concentrated stock with short-term gains | ~$19,700 (24% + 3.8% NIIT + 5% MA) | $14,280 when the gain returns as long-term (23.8% combined) | ~$5,400 permanent, plus years of deferral |
| $3M portfolio, holds the replacement position for life | $14,280 deferred | $0 — heirs receive a stepped-up basis | $14,280 permanent |
The same $60,000 of losses is worth roughly $500 to one household and $14,280 to another. That spread is what the “0.5% to 1% of tax alpha every year” claim papers over. Tax alpha is not a property of the strategy — it is a property of your tax situation.
When does tax-loss harvesting genuinely pay off?
Four cases, in rough order of value.
- You hold the replacement position until death. The big one, rarely mentioned. Heirs inherit at date-of-death value and the embedded gain — including the gain you manufactured by lowering your basis — disappears. Deferral becomes permanent forgiveness. Harvesting is worth most to the people least likely to ever sell.
- You have short-term gains to offset. Short-term gains are taxed as ordinary income, up to 37% federally. Converting a 37% liability into a future 15% or 20% one is permanent rate arbitrage, not a deferral trick.
- You are unwinding a concentrated position. Banked losses are what let you sell down a large single-stock holding without a punishing bill. This is where I see harvesting do the most good.
- A new taxable account in a bad market. Losses cluster in the first few years after funding. A 2022-style drawdown in year two of a $2M account can throw off six figures of harvestable losses.
That last point deserves emphasis. Harvesting is a depleting resource: every loss you take lowers your basis, which makes the next loss harder to find. A strategy sold as a recurring annual benefit is in reality front-loaded, and eventually runs dry.
When is tax-loss harvesting a waste of time?
When your capital gains rate is already 0%, when your money is all in retirement accounts, or when the complexity exceeds the tax saved.
The 0% case catches thoughtful retirees. In 2026 a married couple filing jointly pays 0% on long-term capital gains up to $96,700 of taxable income. If you live on $110,000 a year from a taxable account and Social Security, you may already be realizing gains at 0% federally. Harvesting to shelter a gain that was never going to be taxed is paperwork, and it burns basis you may want in a future high-income year.
It can also crowd out something better. Every dollar of a low bracket filled with harvesting is a dollar not used for a Roth conversion in retirement. Between retiring and starting required minimum distributions at 73, that conversion capacity is usually the scarcer resource — I would rather a client spend a low-income year converting IRA dollars than chasing a $500 harvesting benefit.
What are the wash-sale traps that erase the benefit?
The wash-sale rule disallows your loss if you buy a “substantially identical” security within 30 days before or after the sale — a 61-day window. Four traps cause nearly every wash sale I see.
- Automatic dividend reinvestment. A reinvested dividend inside that window is a purchase, triggering a partial wash sale on the fund you just harvested. Almost nobody remembers to switch it off first.
- Buying the same fund in your IRA. The expensive one. Per IRS guidance, a wash sale created by an IRA purchase means the disallowed loss is permanently lost — it is not added back to basis the way it would be in a taxable account. You do not defer the loss; you destroy it.
- Your spouse’s account. The rule applies across a married couple’s accounts.
- Swapping an index fund for a near-clone. Selling one S&P 500 fund and buying another sponsor’s fund tracking the identical index is aggressive; moving to a distinct index is cleaner. IRS Publication 550 covers the mechanics.
Does Massachusetts treat harvested losses like the IRS does?
No — and that surprises people who assume their federal tax software handled the state side correctly.
Massachusetts taxes long-term capital gains at the same 5% flat rate as ordinary income, with no preferential capital gains structure. That cuts both ways: a resident sitting in the 0% federal bracket still owes 5% to the state, so a harvested loss is not quite as worthless as the federal math suggests. But the state’s rules for applying net losses against other income are much narrower than the federal $3,000 allowance, so your state and federal carryforwards will not match. Confirm current treatment against the Massachusetts DOR’s personal income tax guidance.
There is also a surtax angle. Capital gains count toward Massachusetts taxable income for the 4% surtax on income above $1,083,150. Harvesting losses in the same year you sell a business, a rental property, or a large concentrated position is one of the few clean levers for staying under that line — I covered the mechanics in the Massachusetts millionaires tax and what the 4% surtax means.
How does a flat-fee advisor think about this differently?
Harvesting is a good example of how the fee model shapes the advice.
An advisor billing a percentage of assets has an incentive to promote it as a headline service: it is visible, quantifiable-sounding activity that helps justify a fee scaling with your portfolio. “We generated $40,000 of tax alpha this year” is a satisfying line in a review meeting — even when most of it is a deferral you will pay back.
Evergreen Wealth Management is a fee-only fiduciary firm in Boston charging a flat monthly fee, bundled, whether you have $1 million or $8 million with us. I have no reason to inflate what harvesting is worth or to trade your account to show activity. If you are the 0% bracket retiree in the table above, the honest answer is “this isn’t worth doing — let’s talk about Roth conversions instead,” and saying that costs me nothing. You can see how pricing works on our flat-fee structure page and how we trade in our approach to investment management.
Harvested losses are worth dramatically more when there’s a large gain waiting to absorb them, which is exactly the situation for anyone holding one outsized position. For how the two fit together, see my breakdown of how to diversify a concentrated stock position — where banked losses can be worth 23.8% to 26.3% of face value instead of the $3,000-a-year trickle.
Frequently Asked Questions
How much can I deduct in capital losses each year?
Capital losses offset capital gains without limit. Beyond that, you can deduct up to $3,000 of net losses against ordinary income per year federally ($1,500 if married filing separately). Unused losses carry forward indefinitely — but at $3,000 a year, a $60,000 carryforward takes 20 years to absorb if you never realize offsetting gains.
Can I harvest a loss and buy the investment back right away?
Not the same or a substantially identical security — the wash-sale rule disallows the loss if you repurchase within 30 days either side of the sale. You can buy a genuinely different investment immediately, which is why harvesting normally means swapping into a fund tracking a different index rather than sitting in cash.
Do I need an advisor to do tax-loss harvesting?
No. For a simple portfolio of index funds, harvesting is straightforward enough to do yourself, and paying a percentage-of-assets fee for it is poor value. An advisor earns their keep on the surrounding judgment: whether harvesting beats a Roth conversion this year, how it interacts with Medicare IRMAA brackets and the Massachusetts surtax, and how to sequence it against a concentrated position. At Evergreen, that judgment is part of the flat monthly fee, not a line item that grows with your balance.
The bottom line
Tax-loss harvesting is a legitimate tool dressed up as something bigger. It is worth real money with short-term gains to offset, a concentrated position to unwind, or a long horizon ending in a step-up in basis. It is worth close to nothing if you are already in the 0% capital gains bracket or your assets sit mostly in retirement accounts. Ask what it is worth on your return — and what you gave up to get it.
If you want a straight answer on whether harvesting is doing anything meaningful in your portfolio, here’s how becoming a client works. You can also read more about my background and approach.
Nick Stevens, CFP® is the founder of Evergreen Wealth Management in Boston, a flat-fee financial planning and investment management firm. Evergreen charges a fixed monthly fee regardless of portfolio size. Learn more about how we work at our fee structure or get in touch at contact us.