The Roth Conversion Window

Why the Years Between Retirement and RMDs Could Be Your Most Valuable Tax Opportunity

Most people spend their working years focused on accumulating retirement assets. Fewer think carefully about the tax structure of those assets — until they retire and discover that a large traditional IRA creates a tax obligation that can grow every year.

Required minimum distributions (RMDs) begin at age 73 under current law. Before that age, most retirees who have left the workforce experience a meaningful drop in income. This creates a window — often five to fifteen years — when your taxable income may be temporarily lower than it will ever be again.

What Makes This Window Significant

When you retire before RMDs begin, your traditional IRA or 401(k) balance can keep growing tax-deferred. Every year of growth means more money that will eventually be forced out as taxable income — on a schedule you do not control, at rates you cannot predict.

RMDs are calculated as a percentage of your account balance each year, and that percentage increases with age. A retiree with a $2 million IRA at 73 might face initial RMDs of $75,000 or more annually.

The Roth conversion strategy uses the window before RMDs begin to convert some or all of a traditional IRA to a Roth IRA, paying taxes now at a potentially lower rate, and eliminating future RMDs on the converted amount.

The Math of Conversion

Converting is not free — you pay income tax on the converted amount in the year of conversion. The question is not whether to avoid the tax, but when to pay it and at what rate.

Converting $100,000 in a year when you are in the 22% bracket costs approximately $22,000 in federal tax. If that same $100,000 remains in a traditional IRA and is distributed 15 years later in the 32% bracket, the tax cost is $32,000 — and the underlying balance may have grown, meaning even more tax is owed.

What Can Complicate the Analysis

Medicare premium surcharges (IRMAA). Medicare Part B and Part D premiums are income-tested. Converting too much in a single year can trigger IRMAA surcharges that partially offset the conversion benefit.

Social Security taxation. Up to 85% of Social Security benefits can be taxable depending on income. Adding conversion income can push more Social Security into the taxable range.

Estate planning considerations. Roth IRAs passed to heirs are generally income tax-free. For high-net-worth households with estate planning objectives, the Roth conversion can help serve both income tax and estate tax goals simultaneously.

Widow's penalty. When one spouse dies, the survivor often transitions from married-filing-jointly to single filing status. Converting during the joint filing years, while the wider brackets are available, is a common protective strategy.

How Conversion Sequencing Works

An effective approach is not converting everything at once, but filling brackets deliberately over multiple years. A couple in the 22% bracket might convert enough each year to stay at the top of that bracket — not crossing into 24% — while steadily reducing the traditional IRA balance over a 10-year window.

This requires multi-year modeling that accounts for Social Security start dates, anticipated RMD amounts, investment returns, life expectancy assumptions, and estate goals.

Converting an employer plan account to a Roth IRA is a taxable event. Increased taxable income from the Roth IRA conversion may have several consequences including (but not limited to) a need for additional tax withholding or estimated tax payments, the loss of certain tax deductions and credits, and higher taxes on Social Security benefits and higher Medicare premiums. Be sure to consult with a qualified tax advisor before making any decisions regarding your IRA.

This article is for educational and informational purposes only. It is not investment, tax, or legal advice. Tax laws are subject to change. Consult a qualified tax advisor before making conversion decisions. We do not provide tax advice or tax preparation services.