Every year, thousands of retirees watch helplessly as Required Minimum Distributions push them into higher tax brackets, inflate their Medicare premiums, and increase the tax burden on their Social Security benefits. The frustrating part? For many of these retirees, there was a window of opportunity sitting wide open for years before RMDs began. A multi year Roth conversion strategy exploits that window methodically, converting pre tax IRA dollars into tax free Roth dollars during the lower income years between retirement and age 75. The math is significant, the variables are numerous, and the potential savings can reach well into six figures over a couple's lifetime. To illustrate exactly how this works, let us walk through a detailed case study.

Note: The following case study is entirely hypothetical and created solely for illustrative purposes. No actual client data has been used. Individual results vary significantly based on personal circumstances, tax law changes, and market performance.

Meet David and Karen: A Hypothetical Couple at the Crossroads

David is 63 and recently retired from a career in engineering. Karen is 61 and plans to retire at the end of this year. Here is a snapshot of their financial picture for 2026:

  • Traditional IRA and 401(k) balances: $1,850,000 combined
  • Roth IRA balances: $120,000 combined
  • Taxable brokerage account: $480,000
  • Karen's pension: $24,000 per year, beginning at age 62
  • Social Security: David plans to claim at age 67 ($2,950 per month); Karen plans to claim at age 65 ($1,800 per month)
  • Annual spending need: $110,000 after tax
  • Birth year after 1960: Under SECURE 2.0, RMDs begin at age 75

At first glance, David and Karen appear to be in excellent shape. But there is a ticking clock embedded in their balance sheet. That $1,850,000 in traditional retirement accounts will grow. Assuming a modest 6% annual return and no withdrawals beyond spending needs, those accounts could swell past $3,100,000 by the time David turns 75. At that point, his first RMD alone would be roughly $126,000. Under 2026 OBBB law, every dollar of it would be taxed as ordinary income, stacked on top of Social Security, Karen's pension, and any other income sources. The result is a tax bracket collision that is entirely foreseeable and, with planning, substantially avoidable.

The Golden Window: Why the Years Before 75 Matter So Much

The period between retirement and the onset of RMDs is often the lowest income stretch a retiree will experience for the rest of their life. For David and Karen, this window varies in stages as income sources phase in over time. Understanding each stage is critical to designing the right conversion amounts under the new permanent brackets.

Stage 1: (Years 1 and 2). Neither David nor Karen collects Social Security or the pension yet. Under the 2026 OBBB law, the standard deduction for a married couple filing jointly is $32,200. This means their first $32,200 of ordinary income is effectively tax free. The permanent 10% bracket covers the next $24,800, and the 12% bracket extends to $100,800 of taxable income. This means David and Karen could realize up to roughly $133,000 in total ordinary income before crossing into the 22% bracket. If they only need $110,000 in after tax spending and source some from their brokerage basis, they have massive capacity in the 10% and 12% brackets for conversions.

Stage 2: (Years 3 and 4). Karen's pension kicks in at 62, adding $24,000 per year in taxable income. That pension consumes roughly 24% of their available 10% and 12% bracket space. This is a detail that many retirees overlook: pension income is a permanent bracket consumer. Under OBBB, planning must account for this to avoid pushing conversion dollars into the 22% or 24% brackets prematurely.

Stage 3: Age 67 onward (David claims Social Security). David claims $35,400 per year. Although Social Security taxation formulas remain complex, David and Karen will likely see 85% of their benefits taxed as ordinary income once conversions are factored in. This adds roughly $30,090 to their taxable income baseline, further shrinking the room available in the 12% bracket.

Stage 4: Age 65 and the OBBB Bonus Deduction. Once David and Karen turn 65, they become eligible for the OBBB Bonus Senior Deduction of $6,000 each. However, this $12,000 bonus begins to phase out if their modified adjusted gross income exceeds $150,000. This is exactly where careful analysis is required to determine if it makes sense to go slightly over the deduction thresholds if it saves in lifetime taxes and not just on a year by year tax basis. Often, sacrificing a portion of this deduction now to execute a larger conversion can lead to much higher net wealth over a thirty year retirement.

Key insight: The OBBB law has introduced new variables that require precise analysis. While lower rates are now permanent, the senior bonus deduction phase out creates a scenario where conversions might slightly increase current taxes by reducing that specific deduction. However, professional analysis is required to determine if exceeding these thresholds makes sense on a lifetime tax basis. Often, paying a slightly higher tax today to protect the deduction is less efficient than maximizing the conversion window to save six figures in the long run.

Running the Numbers: Two Scenarios Over 20 Years

To quantify the impact, we modeled two scenarios for David and Karen from age 63 through age 83 using the 2026 OBBB framework. Both assume 6% annual portfolio growth and 2.5% inflation.

Scenario A: No Roth Conversions. Their traditional accounts grow to approximately $3,120,000 by age 75. The first year RMD is roughly $126,800. Combined with $57,000 in Social Security and $24,000 in pension, their total income exceeds $207,000. Under OBBB, their $12,000 senior bonus deduction is partially phased out because their income is above $150,000. Federal tax bill in that first RMD year lands around $24,500. Over 20 years, total estimated federal income taxes paid: approximately $442,000.

Scenario B: Strategic Multi Year Roth Conversions. David and Karen convert roughly $100,000 per year during the first two years, filling the 10% and 12% brackets. As income sources phase in, they taper conversions to stay below the $150,000 OBBB senior deduction phase out threshold in their later 60s. Total converted over the window: $710,000. By age 75, the traditional account is reduced to roughly $1,980,000. The RMD is now only $80,500, and they qualify for the full $12,000 OBBB senior bonus deduction because their income is lower.

Over the same 20 year period, total estimated federal income taxes paid: approximately $314,000.

That is an estimated lifetime tax savings of $128,000. By utilizing the OBBB law to protect the new senior deductions while lowering the future RMD burden, David and Karen have significantly improved their long term outcome.

The Hidden Multipliers: IRMAA, Social Security Taxation, and Surviving Spouse Risk

Beyond the direct tax savings, three hidden multipliers amplify the value of Scenario B. First is IRMAA, the Medicare surcharge that triggers when MAGI exceeds certain thresholds. For 2026, the first tier for joint filers begins at $218,000. Under Scenario A, David and Karen's RMDs and Social Security will frequently flirt with or cross this line as they age, potentially adding $2,400 to $6,000 in annual surcharges. Because Roth withdrawals do not count toward this threshold, Scenario B provides a permanent shield against these cliffs.

Second is the interaction with Social Security taxation. By lowering the traditional IRA balance, David and Karen reduce the amount of provisional income generated each year. This means more of their Social Security check stays in their pocket rather than being handed over to the IRS. In many cases, a well timed conversion strategy can shift a household from having 85% of their benefits taxed down to 50% or even 0%, depending on other income sources.

Finally, there is the Surviving Spouse Risk, often called the widow's penalty. When one spouse passes away, the survivor must file as a single individual. Under OBBB law, the standard deduction is cut in half and tax brackets become much narrower. Scenario A leaves a surviving spouse with a massive traditional IRA and mandatory RMDs that must be reported on a single return, often pushing them into the 28% or 33% brackets. Scenario B provides the survivor with a flexible, tax free Roth bucket that can be accessed without increasing taxable income, preserving wealth during an already difficult transition.

Effective retirement planning is not about the next twelve months; it is about the next thirty years. At Pantile, we use these engineered strategies to help you keep more of what you have built.