Is Your Retirement Portfolio a Tax Bomb?
A warning to high earners and super savers: That massive 401(k) or traditional IRA that you worked so hard to build may become a big problem in retirement, resulting in huge tax bills and Medicare surcharges. Here’s what you need to know, and what you can do about it.
Conventional wisdom suggests you should save everything you can in tax-deferred retirement accounts to minimize taxes in the current year and benefit from tax-sheltered growth. For many, that may still be good advice. Certainly, you should be saving everything you can for retirement. However, for high earners who save a lot, saving in tax-deferred accounts may prove to be bad advice. Why?
This article is part one of a seven-part series. Today’s article provides an overview of the issues and potential solutions.
Snowballing Required Minimum Distributions
Tax-deferred savings have an associated tax liability that you will have to pay someday. The IRS will only let you avoid taxes for so long. Withdrawals from tax-deferred accounts are taxed as ordinary income. You may take withdrawals without penalty from tax-deferred accounts starting at age 59½, but many investors wait to make withdrawals until they are required to take required minimum distributions (RMDs) at age 72.
From just $107.88 $24.99 for Kiplinger Personal Finance
Become a smarter, better informed investor. Subscribe from just $107.88 $24.99, plus get up to 4 Special Issues
Sign up for Kiplinger’s Free Newsletters
Profit and prosper with the best of expert advice on investing, taxes, retirement, personal finance and more - straight to your e-mail.
Profit and prosper with the best of expert advice - straight to your e-mail.
Your tax liability continues to grow over time through contributions, employer matches and your investment return. Eventually, this growing tax liability can snowball, but most investors have no idea of the damage it can cause in retirement.
For example, imagine a couple aged 40 who have saved $500,000 combined in pre-tax 401(k) accounts. Presumably, this couple is tracking well for a secure retirement. If they keep maxing out pre-tax 401(k) contributions and each receive a $6,000 employer match, their 401(k) accounts will have grown to an impressive $7.3 million by retirement at age 65. They’re in great shape, right?
The problem is that their pre-tax savings represents a growing tax liability. The couple’s first RMDs will exceed $435,000 at age 72 and are likely to grow as the couple ages, reaching $739,000 at age 80.
Recall that RMDs are taxed as ordinary income. Do you think they may have a tax problem in retirement?
Medicare Means Testing
The story doesn’t end there, it gets worse. High RMDs are likely to trigger Medicare means testing surcharges (avoidable taxes by a different name) during retirement in the form of higher premiums on Medicare Part B (doctor visits) and Part D (prescription drugs). The couple in our example above is projected to pay $1.5 million in Medicare means testing surcharges through age 90.
Tax Burden for Heirs
At death, assets remaining in inherited tax-deferred accounts have never been taxed, so the tax liability passes to your heirs. The 2019 SECURE Act eliminated the stretch IRA, which allowed heirs to stretch out RMDs from inherited IRAs over their projected life expectancy. Under the new law, RMDs for inherited IRAs no longer exist, but the entire account must be depleted within 10 years, and every withdrawal is taxed as ordinary income at the heirs' marginal tax rate. Our example couple is projected to leave $16.1 million of tax-deferred assets (and the associated tax liability) to their heirs at age 90.
These are not tax issues unique to the super-rich. The couple in this example is upper-middle class, and are simply good savers doing exactly what conventional wisdom has suggested they do. But they clearly need a plan that balances the benefits today of saving in tax-deferred accounts against the tax liabilities this creates for them in retirement. Yet most financial advisers and CPAs focus almost exclusively on minimizing taxes in the current year, without regard to the long-term consequences in retirement.
Planning Strategies to Defuse a Tax Bomb
The solution to these issues typically requires implementation of a multifaceted strategy over many years. Some of the strategies I use with my clients include the following:
Shift Savings from Pre-Tax to Roth Accounts
You’ll lose the tax deduction in the current year, but your tax-free savings will snowball into the future in a good way. This is also the easiest strategy to implement. Many of my clients aren’t aware they have a Roth option in their 401(k)/403(b) or mistakenly think they can’t contribute to one because of income limits, but that’s not true, so find out if your plan offers a Roth option.
In addition, if you have a high-deductible medical plan, contribute the maximum amount ($7,300 in 2022 if married) to the associated health savings account (HSA). Pay your medical expenses out of pocket (not from the HSA account) and invest the account aggressively so it grows to cover medical expenses in retirement. An HSA is one of the few accounts where you get a tax deduction on contributions and money is tax-free when withdrawn (for medical expenses).
Take Advantage of Asset Location
With this strategy, investors place different asset classes into different tax buckets (taxable, pre-tax, tax-free). As an example, asset location typically places investments with low expected returns, such as bonds, into tax-deferred accounts and investments with high expected returns, such as small value or emerging market stocks, into tax-free Roth accounts. The net effect is that your tax-deferred accounts will grow more slowly (and so will your future tax liability), while your tax-free accounts will grow the most.
Few investors have even heard of asset location and it can be hard to implement, but it can significantly reduce your taxes in retirement and increase your after-tax wealth.
Consider Roth Conversions
A Roth conversion involves transferring money from an existing tax-deferred account to a tax-free Roth account. The transfer amount usually is fully taxable as ordinary income. This is a good strategy to consider in low-income years, especially for people who retire early in their 50s and early 60s who may have several years to do conversions before Medicare means testing surcharges, Social Security income, and RMDs kick in. Many of my clients do annual Roth conversions early in retirement.
Saving for retirement is a good thing, but how you choose to save your money can be just as important as how much you save. Sometimes conventional wisdom can lead you astray.
Here are the links to the rest of this series that dives into the issues of retirement tax bombs and their solutions:
- Part 1: Is Your Retirement Portfolio a Tax Bomb?
- Part 2: When It Comes to Your RMDs, Be Very, Very Afraid!
- Part 3: RMDs Can Trigger Massive Medicare Means Testing Surcharges
- Part 4: Will Your Kids Inherit a Tax Bomb from You?
- Part 5: How to Defuse a Retirement Tax Bomb, Starting With 1 Simple Move
- Part 6: Using Asset Location to Defuse a Retirement Tax Bomb
- Part 7: Roth Conversions Play Key Role in Defusing a Retirement Tax Bomb
- Bonus article 1: 2 Ways Retirees Can Defuse a Tax Bomb (It’s Not Too Late!)
- Bonus article 2: Can My Pension Trigger a Retirement Tax Bomb?
Profit and prosper with the best of Kiplinger's advice on investing, taxes, retirement, personal finance and much more. Delivered daily. Enter your email in the box and click Sign Me Up.

David McClellan is a partner with Forum Financial Management, LP, a Registered Investment Adviser that manages more than $7 billion in client assets. He is also VP and Head of Wealth Management Solutions at AiVante, a technology company that uses artificial intelligence to predict lifetime medical expenses. Previously David spent nearly 15 years in executive roles with Morningstar (where he designed retirement income planning software) and Pershing. David is based in Austin, Texas, but works with clients nationwide. His practice focuses on financial life coaching and retirement planning. He frequently helps clients assess and defuse retirement tax bombs.
-
Forget FIRE: Why ‘FILE’ Is the Smarter Move for Child-Free DINKsHow shifting from "Retiring Early" to "Living Early" allows child-free adults to enjoy their wealth while they’re still young enough to use it.
-
7 Tax Blunders to Avoid in Your First Year of RetirementA business-as-usual approach to taxes in the first year of retirement can lead to silly trip-ups that erode your nest egg. Here are seven common goofs to avoid.
-
How to Plan for Social Security in 2026's Changing LandscapeNot understanding how the upcoming changes in 2026 might affect you could put your financial security in retirement at risk. This is what you need to know.
-
7 Tax Blunders to Avoid in Your First Year of Retirement, From a Seasoned Financial PlannerA business-as-usual approach to taxes in the first year of retirement can lead to silly trip-ups that erode your nest egg. Here are seven common goofs to avoid.
-
How to Plan for Social Security in 2026's Changing Landscape, From a Financial ProfessionalNot understanding how the upcoming changes in 2026 might affect you could put your financial security in retirement at risk. This is what you need to know.
-
6 Overlooked Areas That Can Make or Break Your Retirement, From a Retirement AdviserIf you're heading into retirement with scattered and uncertain plans, distilling them into these six areas can ensure you thrive in later life.
-
I'm a Wealth Adviser: These Are the 7 Risks Your Retirement Plan Should AddressYour retirement needs to be able to withstand several major threats, including inflation, longevity, long-term care costs, market swings and more.
-
High-Net-Worth Retirees: Don't Overlook These Benefits of Social SecurityWealthy retirees often overlook Social Security. But timed properly, it can drive tax efficiency, keep Medicare costs in check and strengthen your legacy.
-
Do You Have an Insurance Coverage Gap for Your Valuables? You May Be Surprised to Learn You DoStandard homeowners insurance usually has strict limits on high-value items, so you should formally "schedule" these valuable possessions with your insurer.
-
8 Practical Ways to Declutter Your Life in 2026: A Retirement 'Non-Resolution' ChecklistHere's how to stop wasting your energy on things that don't enhance your new chapter and focus on the things that do.
-
To Retire Rich, Stop Chasing Huge Returns and Do This Instead, Courtesy of a Financial PlannerSaving a large percentage of your income, minimizing taxes and keeping spending in check can offer a more realistic path to retiring rich.