TLH + Roth Conversion = Grafting

Yes, you can harvest losses in your taxable account and do a Roth conversion in the same calendar year, and in a down market each move makes the other more valuable: the losses wipe out capital gains, while depressed asset values mean the conversion buys more future tax-free growth per dollar of tax paid. The caveat is that capital losses do not offset conversion income directly; the combination compounds two separate benefits rather than canceling the conversion's tax bill.

How the Two Moves Work Together

Tax-loss harvesting (TLH) means selling a depreciated position in your taxable account, locking in the capital loss, and immediately reinvesting in something similar enough to maintain your market exposure.

A Roth conversion moves pre-tax dollars from a traditional IRA (or old 401(k)) into a Roth IRA. The amount is added to your ordinary income that year; you pay tax now and the money grows tax-free permanently.

Reducing your net capital gain exposure in the conversion year can keep you out of a higher bracket, or let you convert more while staying inside your target bracket.

The Rules and the Traps

Capital losses do not directly offset conversion income. Conversion income is ordinary income, not capital income; the indirect benefit runs through your bracket position and potentially the 3.8% Net Investment Income Tax (NIIT).

The wash-sale rule applies to the harvest. Buy the same or a substantially identical security within 30 days before or after the sale and the loss is disallowed. Reinvest in something correlated but not identical.

IRMAA look-back matters near Medicare age. A large conversion shows up in your income two years later for Medicare premium surcharges. At 61 or 62, run a projection first; for younger HENRYs it is less immediate.

Carryforward losses are a durable asset. Excess losses carry forward indefinitely. Think of a large carryforward balance as a tax coupon book, ready for future gain events like an asset sale, a business exit, or a concentrated position liquidation.

A Worked Example

An illustrative client: 42 years old, $480,000 household income, a $900,000 taxable account, and $600,000 in a rollover IRA, in a year when equity markets are down 18%.

She harvests $85,000 in losses and reinvests in comparable funds the same day. That zeroes out gains realized earlier in the year, applies the $3,000 ordinary income offset, and leaves $82,000 as a carryforward. Because the IRA has also declined, converting $120,000 costs a smaller share of the portfolio's future value than at peak valuations. The losses do not reduce the conversion tax directly, but she pays no capital gains tax that year and buys permanently tax-free growth on assets that are, in a real sense, on sale.

How This Connects to Tax-Loss Harvesting

This strategy lives inside the Grafting layer of the Sporos Doctrine: combining Roth conversions and tax-loss harvesting to reshape a portfolio's tax character over time. For the underlying mechanics and wash-sale rules, the parent pillar Tax-Loss Harvesting: How to Turn a Down Market Into Real Tax Savings covers the full picture.

Frequently Asked Questions

What is the right conversion amount if I am also harvesting losses?

Run a bracket projection first; the goal is usually to fill a bracket, not cross into the next one. Model wages, other ordinary income, the conversion, and remaining gain exposure after harvesting together.

Can I harvest losses in a 401(k) or IRA?

No. Tax-loss harvesting only applies to taxable brokerage accounts, because losses inside tax-deferred accounts have no tax consequence.

Is there a minimum loss threshold that makes this worth doing?

As a practical matter, I focus on losses of $10,000 or more per position. Below that, the planning effort starts to exceed the benefit unless the trade is clean.

Does this strategy work in every down market year?

The math works whenever you have unrealized losses and pre-tax dollars worth converting, but the conversion decision depends on your income year. A year with unusually high W-2 income may not be the right conversion year even if losses are available.

What to Do Next

What decides this for you. Whether you have harvestable losses and conversion headroom in the same tax year. Both, together. Either alone is a smaller opportunity.

Where it goes wrong. People assume harvested losses offset conversion income dollar for dollar, and they mostly do not. Capital losses offset capital gains first, and only $3,000 a year reaches ordinary income, which is what a conversion generates. So a $50,000 harvest paired with a $50,000 conversion does not produce a tax-free conversion, and planning as though it will produces a bill nobody budgeted for. The genuine benefit is real but different: the carryforward keeps working for years, and the down market that created the losses also lowered the value of the shares being converted.

Worth a conversation if markets are down and you are considering both, or you are carrying losses forward from a previous year and are not sure how much is left. The interaction is worth capturing and it is not the one most articles describe. Book a call.

The information provided is for educational purposes only and does not constitute investment, legal, or tax advice. Tax law changes frequently — verify current rules before acting. Consult with qualified professionals for guidance specific to your situation.