The Pre-RMD Window: Why the Years Before Age 73 Matter for Retirement Taxes

A Rare Stretch of Flexibility

For many people, retirement income arrives on a fixed schedule. Social Security lands each month, pensions pay out on their own terms, and eventually the IRS requires withdrawals from tax-deferred accounts. But there is often a window, roughly between the day paychecks stop and the year required minimum distributions (RMDs) begin, when a retiree has more control over taxable income than at almost any other point in life.

Under current IRS rules, many owners of traditional IRAs and workplace plans such as 401(k)s generally must begin taking RMDs at age 73. Before that milestone, some retirees are living on savings, part-time income, or Social Security they have chosen to delay. That combination can leave taxable income unusually low and, more importantly, unusually adjustable.

Once RMDs begin, the picture changes. The government sets a minimum you must withdraw each year based on your account balance and life expectancy, and that amount counts as ordinary income whether you need the money or not. At that stage, tax planning becomes less optional because a floor has been placed under your income.

Why the Window Closes at 73

The age-73 threshold matters because RMDs are calculated from your prior year-end account balance divided by an IRS life expectancy factor. The larger the balance, the larger the required withdrawal. For someone who has spent decades building a traditional IRA or 401(k), that first mandatory distribution can push taxable income noticeably higher.

Because the withdrawal is required, it removes some of the year-to-year discretion a retiree may have enjoyed earlier. You can still make thoughtful decisions, but you are now working around a mandatory number rather than starting from a blank page. That is why the years before 73 draw so much attention from those thinking about long-term tax exposure.

Roth Conversions as One Example

A Roth conversion is one tool retirees sometimes consider during this window. In a conversion, money moves from a traditional, tax-deferred account into a Roth account. The converted amount is treated as taxable income in the year the conversion happens, but future qualified withdrawals from the Roth generally come out tax-free, and Roth IRAs are not subject to RMDs during the original owner's lifetime.

IRS guidance permits Roth conversions regardless of adjusted gross income. There is no income ceiling that disqualifies you, which is a distinction from direct annual Roth contributions, which do have income limits. That flexibility is part of why conversions come up so often in discussions of the pre-RMD years.

The trade-off is timing. The tax bill still lands in the year of the conversion. Converting a large sum in a single year can raise your taxable income substantially for that year, which is why some people look at converting smaller amounts across several lower-income years rather than all at once. The math depends heavily on individual circumstances, current tax brackets, and expectations about future income.

Tax Moves Do Not Stay in One Lane

One of the most overlooked realities of retirement tax planning is that a decision in one area can spill into another. Raising your income through a conversion or a large withdrawal does not only affect your income tax bill. It can also affect what you pay for Medicare.

Medicare uses a surcharge system known as the income-related monthly adjustment amount, or IRMAA. According to the Centers for Medicare & Medicaid Services (CMS), the 2025 IRMAA surcharges begin above $106,000 for single filers and above $212,000 for married couples filing jointly. Above those thresholds, beneficiaries pay higher monthly premiums for Medicare Part B and Part D.

There is a two-year lag built into this system. IRMAA is generally based on your modified adjusted gross income from two years earlier, so a conversion or large withdrawal today can influence your Medicare premiums two years down the road. A person who crosses an IRMAA threshold by even a small amount can face a full surcharge tier, because these thresholds work as cliffs rather than gradual slopes.

Thinking in Systems, Not Silos

The broader lesson is that retirement tax planning often works best when the pieces are viewed together. Income tax brackets, RMD requirements, Social Security taxation, and Medicare surcharges are separate systems, but they respond to many of the same inputs. A change designed to help in one area can create an unexpected cost in another.

That is why the pre-RMD window is worth understanding rather than ignoring. It is not automatically the right time to take action, and every situation is different. But it represents a period when income is often more flexible, when tools like conversions are available without income restrictions, and when decisions can be spread across multiple years before mandatory distributions narrow the choices. Recognizing how these systems stack together is the first step toward understanding the options available before age 73.