Tax Loss Harvesting vs Roth Conversion: A $1,410 Case Study in Pairing Them (2026)

A $20,000 Roth conversion and an $8,000 tax loss can land on the same return and produce a $1,410 swing, depending only on whether you use them together. If you are weighing tax loss harvesting vs Roth conversion for 2026, this case study walks one illustrative filer through the math, line by line, so you can see which lever to pull and in what order.

Most articles treat these two moves as rivals. They are not. One creates a deduction-like benefit (a harvested loss), the other creates taxable income now in exchange for tax-free growth later. They interact on a single Form 1040, and the interaction is where the money is.

Quick note on the numbers: the person below is a hypothetical, built from the 2026 IRS figures, not a real taxpayer. Every threshold comes from the IRS inflation adjustments for tax year 2026 (Rev. Proc. 2025-32); the dollar outcomes are my own arithmetic from those thresholds.

Tax Loss Harvesting vs Roth Conversion: The Setup

Meet a single filer with a salary that leaves $38,000 of taxable income after the 2026 standard deduction of $16,100. Three other facts matter:

• A traditional IRA with plenty of room to convert. She is considering a $20,000 Roth conversion this year.
• A taxable brokerage account holding a fund that is down $8,000 from her cost basis.
• A $5,000 long-term capital gain she already realized this year when she rebalanced another fund.

The question: should she harvest the $8,000 loss, do the conversion, or both, and does the order change anything? Before the answer, you need the 2026 rulebook on a single page.

Sources: IRS Rev. Proc. 2025-32 (2026 inflation adjustments) and IRS Topic No. 409 on capital gains and losses.

What a Harvested Loss Actually Does on Your Return

When you sell an investment at a loss, the IRS makes you net it in a fixed order. Losses first cancel capital gains of the same type, and only then can up to $3,000 of what is left reduce ordinary income. Anything beyond that carries forward to future years with no expiration. You do not get to choose to skip the gains and take the deduction instead, which is exactly why the case study works the way it does. (If you want the break-even math on whether harvesting is worth the hassle at all, our post on why the standard tax loss harvesting advice rarely pays off for small portfolios covers it.)

The harvest also has to be clean. Under the wash-sale rule (IRS Publication 550), buying the same or a substantially identical security within 30 days before or after the sale disallows the loss. Most people sidestep it by swapping into a similar-but-not-identical fund, which keeps the market exposure without voiding the deduction.

Now apply the netting order to our filer. The $8,000 loss first wipes out the $5,000 gain. The remaining $3,000 reduces her ordinary income. Nothing is left to carry forward. Simple enough, but watch what happens to the $5,000 gain in the next section.

What a Roth Conversion Does to the Same Return

A Roth conversion moves money from a traditional IRA to a Roth IRA, and the converted amount is added to your ordinary income for the year. There is no income limit on who can convert, and since the 2017 tax law changes you cannot undo (recharacterize) a conversion after the fact, so the number you pick is the number you pay on. If you hold other pre-tax IRA balances, the pro-rata rule on Form 8606 can make part of the conversion taxable even if you only intended to move after-tax dollars, which is the trap behind many Roth conversion ladder plans.

For our filer, a $20,000 conversion lifts ordinary taxable income from $38,000 to $58,000. That crosses the top of the 12% bracket at $50,400, so part of the conversion is taxed at 22%.

Here is the part most guides skip. Long-term capital gains are stacked on top of ordinary income when determining which rate applies. Before the conversion, her $5,000 gain sat at a total of $43,000 of taxable income, under the $49,450 line, so it was taxed at 0%. After the conversion, that same gain sits above $49,450, so it is taxed at 15%. The conversion made an untaxed gain taxable.

The Numbers: Four Ways to Play It

Using the 2026 brackets, here is her total federal income tax in each scenario. Tax on $35,000 of ordinary income is $3,952; on $38,000 it is $4,312; on $55,000 it is $6,812; on $58,000 it is $7,472.

Read the table in pairs. In scenario 2, harvesting alone saves $360 (the $3,000 ordinary deduction at 12%). The $5,000 of gain it erased was only taxed at 0% anyway, so most of the loss was spent canceling a gain that cost nothing. In scenario 4, the same harvest next to a conversion saves $1,410 against scenario 3: $750 from killing the now-15% gain, plus $660 from the $3,000 ordinary deduction landing in the 22% bracket instead of 12%.

The same $8,000 loss was worth $360 in one year and $1,410 in the other. The loss did not change. The marginal rate it was offsetting did.

Tax Loss Harvesting vs Roth Conversion: Does Order Matter?

Within a single calendar year, the sequence in which you click the buttons does not change the result. The tax code looks at the full year at once, so harvesting in March and converting in November produces the same return as the reverse. What matters is the year each one lands in, and whether the two share it.

That is the real answer to tax loss harvesting vs Roth conversion sequencing. The practical question is not “which first” but “which year pairs them.” Our earlier piece on tax loss harvesting vs Roth conversion and which to do first gets into the trade-off from the planning angle; this case study shows why the pairing, not the clock, drives the savings.

I started modeling my own conversions in a spreadsheet a few years back, mostly out of curiosity about whether the loss harvesting I read about online was worth the bother in a year I also converted. The honest answer: yes, but only because the loss was absorbing gains taxed at a real rate. In my low-income years, harvesting felt productive and barely moved the total. As someone who does his own taxes without an advisor and likes to automate anything repetitive, I now keep a small script that shows the marginal bracket before I touch either lever.

Where the Pairing Breaks Down

The $1,410 is a clean federal number. Real returns have friction the case study leaves out:

• State income tax. Some states tax conversions and capital gains differently, and some do not follow the federal $3,000 limit.
• Income-based thresholds. A conversion raises your adjusted gross income, which can affect ACA premium credits, Medicare premiums for people near age 65, and the 3.8% net investment income tax for higher earners.
• Cash to pay the tax. Paying conversion tax out of the converted money shrinks the amount that gets tax-free growth. Ideally the bill comes from a taxable account.
• A loss you may need later. Burning a harvested loss against a 0%-rate gain can waste it. If you already realized the gain, you cannot avoid netting. If you have not, consider whether a gain harvest at 0% is the better use, a mirror-image idea we cover in our look at tax gain harvesting vs tax loss harvesting.

How to Run This Playbook on Your Own Numbers

1. Find your projected 2026 taxable income. Start from last year’s return, adjust for raises and life changes, and subtract the standard deduction ($16,100 single, $32,200 married filing jointly).
2. Locate yourself relative to the thresholds. The 12% bracket ends at $50,400 (single) or $100,800 (joint). The 0% capital gains rate ends at $49,450 (single) or $98,900 (joint).
3. List your unrealized losses and realized gains. Pull the tax lots from your brokerage so you know which specific lots have losses, not just which funds.
4. Size the conversion first. Decide how much you want to convert up to the top of a bracket you are comfortable with, then see whether it pushes any gains above the 0% line.
5. Harvest into the conversion year. If you will be in a higher bracket this year because of the conversion, a harvest is worth more. In a quiet low-income year, consider saving the harvest, or skip it if the only gains available are taxed at 0%.
6. Avoid the wash sale. Swap into a similar fund (not identical) and do not buy back the original for 31 days, including in an IRA.
7. Document everything. Keep the trade confirmations, your Form 8606 (for conversions) and Form 8949 (for sales). Or, before settling on a conversion amount, run the long-term growth of the converted dollars through the tool below.

Where This Fits in Your Larger Plan

Neither move beats the basics. If you are not yet capturing an employer match, maxing tax-advantaged space, or holding an emergency fund, those come before optimizing a few hundred dollars of harvesting. Our guide to the order of operations for tax-advantaged accounts lays out where each extra dollar should go first. Conversions and harvesting sit well down that list, which is good news: they are optimizations for people who have already done the unglamorous work.

Key Takeaways

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Written by Chris Steve

Chris Steve is a software engineer with a deep interest in personal finance, behavioral economics, and AI. He started Money & Planet to share clear, research-backed money guides — the kind that explain the math instead of pushing products. His writing focuses on long-term wealth building, the psychology behind spending and investing decisions, and the practical tools regular people can use to make smarter financial choices.