Roth Conversion

A Roth conversion is a deliberate decision to prepay tax. Money in traditional IRAs and pre-tax 401(k)s carries an embedded tax bill that comes due whenever it's withdrawn. Converting settles part of that bill now at today's known rates: the amount you convert is taxed as ordinary income in the year of the conversion, and from then on it grows in Roth territory, where qualified withdrawals are tax-free and nothing is forced out during your lifetime. The bet is straightforward. If the rate you pay on the conversion is lower than the rate that money would otherwise face later, converting wins; if not, it loses.

The classic opportunity is the gap between retirement and the start of required minimum distributions. A retiree who stops working at 62 may spend a decade in unusually low brackets before RMDs at 73 or 75 force large taxable withdrawals. Converting in those years fills the low brackets on purpose, shrinks the pre-tax balance that RMDs will be computed on, and builds a tax-free pool. Other common motives include market downturns (converting depressed positions taxes fewer dollars for the same shares), hedging against higher future tax rates, and estate planning, since heirs generally receive Roth accounts income-tax-free while inherited pre-tax accounts arrive with the tax bill attached.

Three cautions carry most of the weight. First, conversions have been irreversible since 2018; the old recharacterization escape hatch is gone, so size the conversion carefully before executing. Second, the added income ripples outward: it can raise Medicare premium surcharges two years later, reduce health-insurance premium credits, and increase the taxable share of Social Security benefits. Third, paying the conversion tax from outside cash rather than from the converted funds preserves the full amount inside the Roth, and for anyone under 59 1/2, paying tax from the IRA itself can trigger a penalty on the withheld portion. Each conversion also starts its own five-year clock before the converted principal can be withdrawn penalty-free by someone under 59 1/2, which matters for early retirees planning to spend converted dollars.

A hypothetical example: Elaine retires at 63 with $900,000 in a traditional IRA. With no salary, her taxable income is low, so she converts $60,000 to a Roth IRA in December. That $60,000 is added to her ordinary income for the year; if it's taxed at an average of about 15%, the conversion costs roughly $9,000, which she pays from her taxable brokerage account rather than from the IRA.

She repeats a similar conversion each year until RMDs begin. The pre-tax balance that will drive her RMD calculations ends up hundreds of thousands of dollars smaller, the converted money grows tax-free, and she has filled brackets at around 15% that her later RMDs might have been taxed well above. Whether that trade actually pays depends on her future rates, which is why conversion plans are usually modeled year by year rather than done all at once.

Pros

• Locks in today's known tax rates on money that would otherwise be taxed at unknown future rates.
• Shrinks future required minimum distributions and builds a pool of tax-free, RMD-free money.
• No limit on the amount converted, no income ceiling, and no earned income requirement.
• Converted dollars pass to heirs income-tax-free, unlike inherited pre-tax accounts.

Cons

• The tax bill is due now and the conversion cannot be undone.
• Added income can trigger Medicare surcharges, reduce health-insurance subsidies, and tax more of your Social Security.
• Converting makes little sense in high-bracket years or when the tax must be paid from the converted funds themselves.
• Each conversion carries its own five-year clock for penalty-free access before 59 1/2.