Roth conversions can dramatically reduce your lifetime tax burden — but only when executed with a coordinated legal, financial, and tax strategy. Learn when a conversion makes sense, how to calculate the true cost, and the critical mistakes to avoid.
What Is a Roth Conversion?
A Roth conversion is the process of moving money from a traditional IRA or 401(k) — where contributions were made pre-tax — into a Roth IRA, where future growth and qualified withdrawals are tax-free. The amount you convert is added to your taxable income in the year of the conversion, meaning you pay ordinary income taxes on it now in exchange for tax-free treatment later.
For many Michigan families, this trade-off is one of the most powerful tax planning tools available — particularly for those who are retired but not yet required to take distributions from their accounts.
The Optimal Window: The 'Roth Conversion Corridor'
The most valuable time to execute Roth conversions is typically the period between retirement and age 73, when Required Minimum Distributions (RMDs) begin. During this window, many retirees have lower taxable income than they will in the future — their salary is gone, Social Security may not have started yet, and RMDs haven't kicked in.
This creates a unique opportunity to 'fill up' lower tax brackets with Roth conversions at a lower cost than you would pay later. For example, if your standard deduction and other deductions bring your taxable income to $30,000, you may be able to convert an additional $44,725 and still remain in the 22% federal bracket (2024 figures for married filing jointly).
The IRMAA Trap: Why Conversions Must Be Carefully Sized
One of the most common and costly mistakes in Roth conversion planning is converting too much in a single year — inadvertently triggering Medicare's Income-Related Monthly Adjustment Amount (IRMAA) surcharges.
IRMAA is calculated based on your Modified Adjusted Gross Income (MAGI) from two years prior. If a large Roth conversion pushes your MAGI above the IRMAA threshold ($206,000 for married couples in 2024), your Medicare Part B and Part D premiums can increase by $3,000 to $12,000 per year — for two years. This can easily wipe out the tax benefit of the conversion.
This is precisely why Roth conversion planning cannot be done in isolation. Your tax advisor needs to know your investment account balances and projected RMDs. Your financial advisor needs to know your current and projected tax brackets. And your estate attorney needs to know how Roth assets will be treated in your estate plan.
Roth Conversions and Your Estate Plan
Roth IRAs have a significant estate planning advantage: unlike traditional IRAs, they are not subject to Required Minimum Distributions during the original owner's lifetime. This means a Roth IRA can continue to grow tax-free for decades, making it one of the most powerful assets to pass to heirs.
However, inherited Roth IRAs are subject to the 10-year rule under the SECURE Act 2.0 — meaning non-spouse beneficiaries must withdraw all funds within 10 years of the original owner's death. While these withdrawals are still tax-free, the timing matters for your heirs' own tax planning.
This is why your estate attorney should be involved in any Roth conversion strategy. The decision of which accounts to convert, how much, and in what order should be made with full awareness of how those assets will ultimately transfer to your heirs.
How MSFE Teaches Roth Conversion Strategy
The Michigan Society for Financial Education covers Roth conversion strategy in depth across multiple educational formats — including our 'Tax-Smart Retirement' webinar series, our in-person Tax Management in Retirement workshop, and our 8-week Retirement Financial Mastery Program.
Our approach is unique because we bring together attorneys, financial advisors, and CPAs to teach this topic jointly — so you understand not just the tax mechanics, but how a Roth conversion interacts with your estate plan, your Medicare costs, and your overall retirement income strategy.