The Best Retirement Tax Window May Come 5 Years Before Social Security and RMDs

One of the most valuable tax-planning opportunities in retirement often appears when income temporarily falls. A person leaves work, salary disappears, Social Security may not have started yet and required minimum distributions are still years away. During that period, taxable income can be substantially lower than it was during the final working years and lower than it may become later in retirement.

That creates an opportunity to make deliberate tax moves before future income becomes harder to control. Roth conversions, capital-gains planning and strategic withdrawals can all be more attractive when ordinary income is temporarily reduced. The challenge is that the window does not stay open forever, and using it poorly can create unnecessary taxes, higher Medicare premiums or lost health-insurance subsidies.

The Window Opens When Earned Income Falls

For many households, the tax window begins shortly after retirement. Salary and bonuses disappear, payroll stops and the household may suddenly move into a much lower tax bracket. If Social Security has also been delayed, taxable income can temporarily drop even further.

This period can last several years, but there is no universal five-year rule. Someone retiring at 62 and delaying Social Security until 70 may have a much longer planning window than someone retiring at 68 and beginning benefits immediately. Required minimum distributions can also begin at different ages depending on birth year, which changes how long the opportunity lasts.

Under current law, RMDs generally begin at age 73 for people who reach age 73 before 2033, while the applicable starting age rises to 75 for younger cohorts. That means a retiree who stops working in the early 60s may have a decade or more before forced distributions begin.

Roth Conversions Can Be Especially Valuable During Low-Income Years

A Roth conversion moves money from a traditional IRA or other eligible pretax retirement account into a Roth account. The converted amount is generally taxable as ordinary income in the year of the conversion, but qualified Roth withdrawals later can be tax-free. Roth IRAs also do not require lifetime RMDs for the original owner.

That trade can be attractive when current tax rates are relatively low and future taxable income is expected to be higher. A retiree may deliberately convert enough each year to fill part of a lower tax bracket rather than waiting until RMDs force larger taxable withdrawals later. The objective is not necessarily minimizing this year’s tax bill, but potentially reducing lifetime taxes.

The process should be gradual because a large conversion can create its own problems. Converting too much at once can push income into a higher marginal bracket, increase Medicare premiums or reduce other tax benefits. A successful conversion strategy usually focuses on how much to convert, not simply whether to convert.

Current Tax Brackets Create Planning Room

For 2026, married couples filing jointly remain in the 12% federal bracket until taxable income exceeds $100,800. The 22% bracket then extends through $211,400, while the 24% bracket runs through $403,550. The standard deduction is $32,200 for married couples filing jointly and $16,100 for single filers.

Those thresholds can create meaningful room for retirees whose employment income has disappeared. A married couple with relatively little other taxable income may be able to convert a portion of a traditional IRA while remaining in a bracket they consider attractive. Another household may deliberately use some of the 22% or 24% bracket because future RMDs are projected to push them into similar or higher rates later.

There is no universal bracket that everyone should fill. The right amount depends on future income, state taxes, account balances, survivor planning and how much future RMD pressure is expected. The tax window should be modeled across several years rather than optimized one year at a time.

Future RMDs Can Create a Tax Problem

Large traditional IRA and 401(k) balances can become less flexible later in retirement because required distributions eventually begin. Once RMDs start, the retiree may have to recognize taxable income even when the cash is not needed for living expenses. That can increase federal taxes and interact with Social Security taxation and Medicare premiums.

The larger the pretax balance, the more valuable early planning can become. Converting part of that balance before RMDs begin may reduce future required withdrawals and create more tax diversification. The retiree gains greater control over whether future spending comes from pretax, Roth or taxable accounts.

The goal is not always to eliminate future RMDs. Doing that could require paying far too much tax upfront. A better objective is often smoothing taxable income across retirement so one period does not become unnecessarily expensive.

Social Security Can Narrow the Window

Social Security can add another layer of taxable income once benefits begin. Federal taxation depends on combined income, which includes adjusted gross income, tax-exempt interest and one-half of Social Security benefits. Up to 85% of benefits can become taxable once combined income exceeds the applicable thresholds.

For individual filers, Social Security taxation begins to become relevant once combined income exceeds $25,000. For married couples filing jointly, the comparable threshold begins at $32,000. These thresholds are not tax rates; they determine how much of the benefit may be included in taxable income.

That means a Roth conversion after Social Security begins can sometimes cause more of the benefit to become taxable. The result can make the effective marginal tax rate on the conversion higher than the ordinary bracket alone would suggest. This is one reason the years before Social Security begins can be especially attractive.

Medicare Can Make Large Conversions More Expensive

Medicare introduces another important threshold. In 2026, the first IRMAA surcharge begins when modified adjusted gross income exceeds $109,000 for single filers or $218,000 for married couples filing jointly. Above those levels, beneficiaries pay higher Part B premiums and additional Part D surcharges.

A Roth conversion can push a retiree above one of those thresholds because the converted amount generally increases modified adjusted gross income. The Medicare impact is usually delayed because IRMAA generally relies on tax information from two years earlier. A conversion in one year can therefore create higher Medicare premiums later.

That does not automatically mean the conversion should be avoided. Paying a temporary surcharge may still be worthwhile if it meaningfully reduces future taxes or RMDs. The decision should compare the total lifetime benefit with the temporary Medicare cost.

The ACA Can Matter Before Medicare

Retirees who stop working before age 65 may face a different income constraint. If health insurance comes through an Affordable Care Act marketplace, Roth conversions can increase modified adjusted gross income and reduce premium-tax-credit eligibility. A conversion that looks attractive from an income-tax perspective can become more expensive when lost health-insurance subsidies are included.

That makes the pre-Medicare tax window more complicated rather than less useful. Some retirees may still benefit from conversions during those years, especially if they receive little or no ACA subsidy. Others may prefer smaller conversions until Medicare begins.

The right strategy depends on the interaction between tax brackets and health-insurance costs. Looking only at federal income tax can miss a large part of the real cost.

Capital Gains Can Compete With Roth Conversions

Retirement tax planning is not limited to pretax accounts. Someone with a taxable brokerage account may also have appreciated investments that can be sold during lower-income years. Depending on taxable income, some long-term capital gains may qualify for a 0% federal rate.

The important issue is that capital gains and Roth conversions both use taxable-income space. A retiree who converts a large IRA balance may reduce the amount of capital gain that qualifies for a lower rate. Conversely, harvesting large gains can push a conversion into a higher bracket.

This is why these decisions should be coordinated rather than handled independently. The best use of a low-income year may involve a combination of Roth conversions and capital-gains realization. The correct mix depends on basis, future tax expectations and portfolio needs.

Delaying Social Security Can Expand the Planning Window

Someone who delays Social Security may create more years in which taxable income is relatively low. That can provide additional room for Roth conversions or realizing gains before Social Security benefits begin. The strategy can be particularly attractive for households with large pretax retirement accounts.

Delaying Social Security also increases the eventual monthly benefit up to age 70. That larger guaranteed income can be valuable later, but it may also increase the portion of retirement spending covered by taxable income. Using the years before benefits begin for conversions can therefore serve two purposes at once.

This is not a universal reason to delay benefits. Health, longevity, survivor needs and portfolio size all matter. The important planning insight is that Social Security timing can affect more than the benefit itself; it can also change the tax window.

The Widow’s Tax Penalty Can Make Early Planning More Important

Married couples should also consider what happens after the first spouse dies. The surviving spouse generally moves from married-filing-jointly tax brackets to single brackets, while potentially keeping much of the same taxable investment income and RMD burden. That can push the survivor into higher marginal rates even when household spending falls.

The 2026 tax brackets show why the issue matters. The 22% bracket begins above $50,400 of taxable income for single filers but above $100,800 for married couples filing jointly. A widow or widower can therefore face higher tax rates on similar income after losing a spouse.

Strategic Roth conversions while both spouses are alive can sometimes reduce that future pressure. This is especially relevant when one spouse is expected to live many years after the other. Retirement tax planning should therefore consider both the joint years and the survivor years.

December 31 Matters Every Year

Roth conversions are tied to the calendar year. If a retiree intends to use the 2026 tax brackets, the conversion must generally be completed by December 31, 2026. Waiting until tax-filing season in 2027 does not recreate the opportunity.

That makes fall tax planning especially important. By late in the year, retirees usually have a better idea of dividends, capital gains, pension income and other taxable items. Those figures can be used to determine how much room remains in the desired bracket.

The missed opportunity is not that retirement tax planning disappears forever after December 31. The problem is that unused tax capacity from one year generally cannot be carried forward. A low-income year that passes without action cannot simply be reopened later.

The Window Eventually Narrows

As retirement progresses, multiple income sources can begin stacking on top of one another. Social Security starts, pensions may begin and RMDs eventually become mandatory. Investment income can add another layer, leaving less room for discretionary tax planning.

This is why early retirement can be unusually valuable from a tax perspective. Retirees may have more control over their taxable income during those years than they will later. Once mandatory distributions begin, some of that flexibility disappears.

The opportunity can be particularly large for households with substantial pretax savings. Years of successful 401(k) contributions created tax deferral while working, but retirement eventually requires deciding when those taxes should be paid. The low-income window can offer a chance to make that decision intentionally.

Roth Conversions Are Not Automatically the Right Move

A conversion should not be judged solely by whether the current tax rate looks low. Future tax rates may be similar or lower, charitable giving plans could make future IRA distributions more tax-efficient, and heirs may have different tax circumstances. Some retirees may also need the cash that would otherwise be used to pay conversion taxes.

State taxes can change the calculation as well. Someone planning to move from a high-tax state to a state with no income tax may be better off delaying some conversions. Someone moving in the opposite direction may benefit from converting before the move.

This is why blanket advice such as “convert everything before RMDs” can be dangerous. The purpose is not to maximize Roth assets at any cost. The goal is to reduce total lifetime taxes while preserving flexibility.

Tax Diversification Is the Real Objective

A retiree with money in traditional retirement accounts, Roth accounts and taxable brokerage accounts has more control over annual taxable income than someone whose entire portfolio is pretax. Different accounts can be used for different spending needs depending on tax conditions.

Traditional IRA withdrawals create ordinary income. Qualified Roth withdrawals generally do not, while taxable brokerage withdrawals are taxed based on gains rather than the full amount withdrawn. That flexibility can help manage tax brackets, Social Security taxation and Medicare premiums.

The low-income window is therefore not only about Roth conversions. It is about deliberately changing the mix of accounts so future retirement spending can be funded more efficiently. Tax diversification becomes another form of financial flexibility.

The Best Strategy Requires a Multi-Year Plan

The biggest mistake is treating each tax year as an isolated problem. A conversion that raises taxes this year may still reduce lifetime taxes if it prevents larger RMDs later. A conversion that looks attractive today may be unnecessary if future taxable income is expected to remain low.

A useful retirement tax projection should estimate income from retirement through the beginning of RMDs and beyond. It should include Social Security, pensions, expected withdrawals, capital gains, Medicare premiums and potential survivor taxes. That broader view makes it easier to identify which years offer the most valuable planning opportunities.

Professional tax and financial advice can be especially useful when the balances are large or multiple thresholds overlap. Roth conversions are irreversible, and the interaction among tax brackets, Medicare, ACA subsidies and Social Security can be complicated. The decision deserves more analysis than simply converting whatever fits below the next bracket.

The Window Is Valuable Because It Does Not Repeat

The years immediately after retirement can look financially quiet, but they may actually be among the most important tax years of someone’s life. Earned income is gone, RMDs have not started and Social Security may still be delayed. That combination can create an unusual level of control over taxable income.

The opportunity does not last forever. Once Social Security and RMDs begin, taxable income may become much more difficult to manage, and some of today’s unused bracket space cannot be recovered. The best retirement tax planning often happens before there appears to be a tax problem.

The goal is not to pay the least tax possible this year. It is to use the temporary flexibility of early retirement to reduce taxes across the rest of retirement. For many retirees, that makes the years before Social Security and RMDs one of the most valuable financial windows they will ever have.

Intended for educational purposes only. Opinions expressed are not intended as investment advice or to predict future performance. Past performance does not guarantee future results. Neither the information presented, nor any opinion expressed constitutes a solicitation for the purchase or sale of any security. Consult your financial professional before making any investment decisions. Opinions expressed are subject to change without notice.

IMPORTANT DISCLOSURES:

• Investment Advisory and Financial Planning Services are offered through Pure Financial Advisors, LLC. A Registered Investment Advisor.

• Pure Financial Advisors, LLC. does not offer tax or legal advice. Consult with a tax advisor or attorney regarding specific situations.

• Opinions expressed are subject to change without notice and are not intended as investment advice or to predict future performance.

• Investing involves risk including the potential loss of principal. No investment strategy can guarantee a profit or protect against loss in periods of declining values.

• All information is believed to be from reliable sources; however, we make no representation as to its completeness or accuracy.

• Intended for educational purposes only and are not intended as individualized advice or a guarantee that you will achieve a desired result. Before implementing any strategies discussed you should consult your tax and financial advisors.