Most people spend decades accumulating wealth, carefully building the nest egg they hope will carry them through retirement. Yet a surprisingly large number of diligent, responsible savers unknowingly surrender thousands of dollars in taxes every year — not because they made reckless decisions, but because they did not realize how tightly interconnected every retirement income source truly is.

Two tax traps in particular deserve your attention before you take your next distribution, file for Social Security, or rebalance your portfolio. Understanding them thoroughly can mean the difference between a retirement spent confidently and one spent wondering where the money went.

Tax Trap #1: Treating Social Security as a Separate Decision from Your Roth Conversion Strategy

When should I file for Social Security?

That question comes up in nearly every retirement planning conversation, and for good reason. Claiming at age 62 gives you immediate income, while waiting until age 70 grows your monthly benefit by roughly 8% for every year you delay beyond your full retirement age [1]. On the surface, it sounds like a fairly isolated financial calculation.

The hidden problem is that the moment you turn on Social Security, you fundamentally reshape your tax landscape for everything else. Specifically, it can dramatically reduce your ability to execute one of the most powerful tax-reduction strategies available to retirees: the Roth conversion.

What Is a Roth Conversion, and Why Does It Matter?

A Roth conversion is the process of moving money from a traditional IRA or 401(k) into a Roth IRA. Because funds in traditional accounts were contributed pre-tax, you pay income tax on the amount converted in the year you move it. In exchange, that money grows tax-free and is distributed tax-free in retirement — and unlike traditional IRAs, Roth IRAs are not subject to Required Minimum Distributions (RMDs) [2].

This strategy is most attractive during what planners often call the "conversion window" — the stretch of years after you stop working but before RMDs begin at ages 73 or 75, depending on your year of birth [3]. During that window, your taxable income may be at its lowest point in decades, creating a genuine opportunity to move IRA funds to a Roth at a relatively modest tax cost.

It is important to acknowledge that Roth conversions carry real costs and are not universally appropriate. You must have liquid funds available to pay the resulting tax bill without drawing down the converted amount itself. And if your current tax rate is not meaningfully lower than your expected future rate, the math may not favor conversion. Always evaluate this strategy in the context of your full financial picture [4].

Why Social Security Timing Can Slam That Window Shut

Here is what most general financial articles fail to explain clearly: Social Security benefits are not taxed the same way ordinary income is taxed. Instead, the IRS uses a formula based on your "provisional income" — which is your adjusted gross income plus any tax-exempt interest plus 50% of your Social Security benefit [5]. When that provisional income crosses certain thresholds, up to 85% of your Social Security benefit can become subject to ordinary income tax.

So the moment you turn on your Social Security benefit and begin receiving that income, your overall income rises — which can:

• Push more of that benefit into a taxable zone
• Simultaneously shrink the available tax bracket "room" you have for Roth conversions
• Potentially push you into a higher Medicare premium bracket, known as IRMAA (the Income-Related Monthly Adjustment Amount) [6]

The result is that a conversion that looked attractively priced at 22% in January may effectively cost you far more once you account for the cascading effect on your Social Security taxation and Medicare surcharges.

A Real-World Illustration: Dan and Wendy

Consider a hypothetical couple — call them Dan (age 68) and Wendy (age 65). They are both retired, debt-free, and have $600,000 in a traditional IRA, supplemented by two modest pension incomes. This scenario is purely illustrative and does not represent any specific clients or guarantee similar outcomes.

Their initial plan was straightforward: convert aggressively within the 22% bracket before RMDs force the issue. But they also had a looming Social Security decision. When the numbers were modeled with both spouses claiming Social Security immediately, the Roth conversions became far more expensive. The added Social Security income triggered higher taxation on those very benefits and created IRMAA surcharges that quietly added hundreds of dollars per month to their Medicare costs.

The more tax-efficient path looked like this:

• Wendy filed for her Social Security benefit at age 65, adding a guaranteed income stream now.
• Their two pensions and modest IRA distributions covered remaining income needs.
• Dan delayed his benefit until age 70 — which kept their combined income lower for two additional years, allowing approximately $150,000 in strategic Roth conversions, all within the 22% bracket, while avoiding IRMAA and minimizing Social Security taxation.

Delaying Dan's benefit also served a secondary purpose: it maximized his monthly payment, providing a larger lifetime income and, critically, a larger survivor benefit if he predeceases Wendy. When one spouse dies, the surviving spouse steps up to the higher of the two Social Security checks — so delaying the larger earner's benefit can provide meaningful financial protection for decades.

The key insight here is that the most tax-efficient Social Security filing decision is rarely the one that looks the best in isolation. It is the one that coordinates most effectively with your Roth conversion window, your RMD exposure, your Medicare premiums, and your long-term income needs simultaneously.

Tax Trap #2: Phantom Tax and the Hidden Cost of Capital Gains in Retirement

The second tax trap is less well-known, which makes it considerably more dangerous. It is sometimes called phantom tax — and it can cause an otherwise unremarkable financial decision, such as taking an extra $1,000 from your IRA for a weekend trip, to carry an effective marginal tax rate approaching 50%.

The 0% Capital Gains Rate Is Real, but It Has Invisible Conditions

The federal tax code does provide a 0% long-term capital gains rate for taxpayers whose income falls below certain thresholds. For a married couple filing jointly in 2025, that threshold is approximately $96,700 in taxable income [7]. Many retirees assume that because they have carefully managed their income to stay below that number, they will owe nothing on the gains from selling appreciated stock or other assets.

The catch is that capital gains are not evaluated in a vacuum. They interact with Social Security's provisional income formula — and that interaction can produce tax consequences that feel, quite accurately, like a ghost knocking on the door uninvited.

How the Trap Springs: Larry and Susan's $1,000 Vacation

Consider another illustrative hypothetical: Larry and Susan, both in their early 70s. In a given year, they receive combined Social Security of $61,000, required minimum distributions of $47,000, and $15,000 in capital gains from a portfolio rebalancing. Their income is comfortably structured. Then they decide to take $1,000 from their IRA for a long weekend away.

What they expect to pay in taxes on that $1,000 IRA distribution: $120 (at the 12% ordinary income rate) [8].

What they actually pay, in total, is closer to $492 — which breaks down as follows:

• $120 in ordinary income tax on the $1,000 IRA distribution itself.
• An additional $102 in ordinary income tax because the IRA distribution increases provisional income, which in turn exposes an additional $850 of their Social Security benefit to the 12% tax rate.
• An additional $270 because that same provisional income shift nudges $1,800 of their previously tax-free capital gains into the 15% capital gains bracket.

The effective marginal tax rate on that single $1,000 IRA withdrawal: roughly 49%. Larry and Susan did not do anything financially irresponsible. They simply did not know the trap existed. That is why it is called phantom tax — the tax liability does not appear in any single category; it materializes across three separate line items simultaneously.

Going Deeper: How to Structure Withdrawals to Minimize the Cascade Effect

The conventional wisdom on retirement withdrawal sequencing is to draw first from taxable accounts (brokerage), then from tax-deferred accounts (IRA/401(k)), and finally from tax-free accounts (Roth IRA). That framework was designed primarily around account longevity, and it remains useful in many contexts.

However, for retirees navigating the intersection of Social Security, RMDs, and capital gains, a modified approach often produces meaningfully better tax outcomes. The logic is straightforward: because IRA distributions have a direct and immediate multiplier effect on how much of your Social Security gets taxed, drawing down your IRA earlier — during low-income years before Social Security begins — can reduce your lifetime tax burden substantially.

Four Practical Strategies to Consider

• Use your pre-Social Security, pre-RMD years for Roth conversions. This is the window where your taxable income is typically at its lowest. Converting IRA funds to Roth now, even at a modest tax cost, may help you avoid far higher taxes later when RMDs and Social Security compound your income.
• Consider drawing from your IRA before activating Social Security. Rather than letting your IRA compound and triggering larger RMDs later, taking modest IRA distributions in the early retirement years can help "right-size" your future RMD exposure while keeping your Social Security income timeline flexible.
• Coordinate capital gains realizations with your Roth conversion years carefully. Selling appreciated assets and executing Roth conversions in the same calendar year can combine to push you into higher ordinary income and capital gains brackets. During high-conversion years, consider deferring large capital gains realizations to a later, lower-income year — and vice versa.
• Evaluate delaying the larger Social Security benefit while the lower earner files sooner. This approach, illustrated with Dan and Wendy above, allows income to flow in from one benefit while preserving the optimal window for tax planning — and it maximizes both lifetime income and survivor protection.

Frequently Asked Questions

Does delaying Social Security always make sense for tax planning?

Not necessarily. The decision depends on your health, life expectancy, income needs, and how aggressively you plan to execute Roth conversions. For some households, filing earlier and accepting a modest increase in tax complexity may be preferable if immediate cash flow is a priority. The point is simply that this decision should not be made in isolation from your broader tax strategy.

What is IRMAA, and how can I avoid it?

IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to your Medicare Part B and Part D premiums when your modified adjusted gross income exceeds certain thresholds [6]. In 2025, the surcharge begins at MAGI above $106,000 for individual filers and $212,000 for married couples filing jointly. Roth conversions, IRA distributions, and capital gains all count toward this threshold. Careful income planning in the years before RMDs begin can help you manage and potentially avoid these surcharges.

Are Roth conversions always a good idea before RMDs begin?

Not universally. A Roth conversion makes the most sense when your current tax rate is materially lower than the tax rate you expect to face in the future, when you have non-IRA funds available to pay the tax bill, and when you have sufficient time for the Roth account to compound before distributions are needed. If your current and expected future tax rates are similar, or if you lack the liquid resources to pay conversion taxes without touching the converted funds, other strategies may be more appropriate.

How do RMDs interact with the phantom tax trap?

Required Minimum Distributions add a layer of complexity because they are non-discretionary. Once you reach the applicable starting age, the IRS requires you to withdraw a minimum amount from your traditional IRA and most employer-sponsored retirement accounts each year, based on your account balance and a published life expectancy table [3]. Those distributions are treated as ordinary income, which feeds directly into your provisional income calculation and can trigger or amplify the phantom tax effect on your Social Security and capital gains. Planning years before RMDs begin — particularly through targeted Roth conversions — is one of the most effective ways to reduce this exposure.

The Bigger Picture: Every Lever Moves the Others

What both of these tax traps illustrate is a fundamental truth about retirement income planning: the tax code is not a collection of separate, independent rules. It is a system of interconnected levers, and pulling one inevitably moves the others. IRA distributions affect Social Security taxation. Social Security timing affects Roth conversion costs. Capital gains affect your provisional income. IRMAA surcharges ripple out from all of the above.

For the saver who spent decades doing everything right — building a diversified portfolio, contributing consistently to tax-deferred accounts, and living within their means — this is the critical transition: moving from accumulation to distribution requires an entirely different kind of financial thinking. The goal shifts from growing the pile to drawing it down strategically, with each decision evaluated not just for its immediate benefit, but for its downstream tax consequences.

The good news is that with proper planning, particularly during the years just before and just after leaving the workforce, these traps are avoidable. You do not have to accept a 49% effective marginal tax rate on a vacation withdrawal. You do not have to watch Roth conversion benefits evaporate into unnecessary Medicare surcharges. With a coordinated strategy, you can keep more of what you have earned — and you can spend it with confidence.

Ready to See Your Full Retirement Tax Picture?

At Phibbs Financial Services, we believe money is most meaningful when it is being used to create experiences and memories, not when it is sitting in an account waiting to be taxed away. Our approach to retirement planning is built around helping you spend without fear, knowing that your income is structured to last and your tax liability is managed with intention.

If you are in the years approaching or just entering retirement, now is the time to look at your full picture: your Social Security filing strategy, your Roth conversion window, your RMD timeline, your capital gains exposure, and how all of those pieces fit together.

We help people create more memories with their money. If you are ready to learn how to spend without fear, schedule your no-cost Retirement Inspection ® at freeretirementinspection.com. There is no pressure and no obligation — only clarity.

Sources

[1] Social Security Administration, "Retirement Benefits: How Credits Affect Your Benefits." ssa.gov/benefits/retirement/planner/delayret.html

[2] Internal Revenue Service, Publication 590-B. irs.gov/publications/p590b

[3] Internal Revenue Service, "Retirement Plan and IRA Required Minimum Distributions FAQs." irs.gov/retirement-plans/retirement-plans-faqs-regarding-required-minimum-distributions

[4] Internal Revenue Service, Publication 590-A. irs.gov/publications/p590a

[5] Internal Revenue Service, Publication 915. irs.gov/publications/p915

[6] Centers for Medicare and Medicaid Services, "Medicare Costs at a Glance." medicare.gov/your-medicare-costs/medicare-costs-at-a-glance

[7] Internal Revenue Service, Revenue Procedure 2024-61. irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2025

[8] Internal Revenue Service, Revenue Procedure 2024-61. irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2025

Disclosures

The material provided is for general educational and informational purposes only and does not constitute personalized investment, legal, or financial advice. All investment strategies, including retirement distribution and tax-efficiency planning, involve inherent risks and potential loss of principal, and past performance is never a guarantee of future market results. Any hypothetical examples or strategies discussed are purely illustrative and may not be suitable for your specific age, tax bracket, or financial situation. Furthermore, while our comprehensive financial planning evaluates strategic wealth outlooks, Phibbs Financial Services LLC does not provide formal tax preparation, legal counsel, or IRS representation. Readers should always consult with a qualified CPA or licensed attorney before implementing any advanced tax or estate strategies mentioned herein.