Can You Save Too Much for Retirement: Taxes, RMDs, and Medicare

Yes, saving too much for retirement in a traditional 401(k) or IRA is a real problem, and the cost shows up in several places at once: forced withdrawals taxed at ordinary income rates, taxable Social Security benefits, Medicare premium surcharges, a compressed tax bill for your heirs, and, at the highest balances, federal estate tax. The larger the tax-deferred account, the harder these effects compound. The good news is that most of them can be softened with planning if you start early enough.

Why Big Tax-Deferred Balances Backfire

Every dollar you pull from a traditional 401(k) or IRA counts as ordinary income in the year you take it.¹ There is no long-term capital gains rate here. If you contributed while sitting in the 22% or 24% bracket during your working years, large distributions in retirement can push you into the 32% bracket (which begins at $201,775 for single filers in 2026) or the 35% bracket (starting at $256,225).²

When that happens, the deferral runs in reverse. You skipped tax at a lower rate and now owe it at a higher one. Across a 20- or 30-year retirement, the cumulative tax on distributions can exceed the savings you gained by deferring in the first place. The bigger your balance, the more pronounced the effect, because you either need larger annual withdrawals to fund your lifestyle or the government eventually forces them.

Hidden Costs: Social Security and Medicare

Your Social Security Benefits Become Taxable

Withdrawals from a retirement account don’t only raise your income tax bill. They can also make your Social Security benefits taxable. The IRS calculates your “provisional income” — adjusted gross income plus nontaxable interest plus half your Social Security benefits — and applies two thresholds. If provisional income falls between $25,000 and $34,000 for a single filer (or $32,000 to $44,000 for joint filers), up to 50% of benefits become taxable. Above $34,000 single or $44,000 joint, up to 85% of benefits are taxable.³

Those thresholds have not been adjusted for inflation since the 1980s. A large tax-deferred balance makes it nearly impossible to stay below them, which effectively adds a layer of tax on income you already planned to spend.

Medicare Premiums Climb With Income

Medicare Part B and Part D premiums also rise once your modified adjusted gross income clears certain levels. These Income-Related Monthly Adjustment Amounts, or IRMAA, are tiered. For 2026, individuals with income above $109,000 (or $218,000 for joint filers) pay a Part B surcharge that starts at $81.20 per month on top of the $202.90 standard premium. At the top tier — income of $500,000 for individuals or $750,000 for joint filers — the total monthly Part B premium reaches $689.90.⁴ Part D carries similar income-based surcharges.

IRMAA uses your tax return from two years earlier. A single large distribution, including a one-time Roth conversion, can raise your premiums for the following coverage year. For retirees with heavy tax-deferred balances, these surcharges act as a hidden tax on every distribution.

Required Minimum Distributions Take Away Your Choice

Even if you don’t need the money, the IRS eventually forces you to withdraw from traditional retirement accounts. Required minimum distributions begin at age 73 under current rules, with a scheduled move to age 75 for those who turn 74 after December 31, 2032.⁵ Each year’s RMD is your prior-year-end balance divided by a life expectancy factor from the IRS Uniform Lifetime Table. As you age, that factor shrinks, so a larger share of the account is pushed into taxable income each year.

Missing an RMD is expensive. The IRS imposes a 25% excise tax on the shortfall. If you catch the error and withdraw the correct amount during the correction window — generally before the IRS assesses the tax or by the end of the second tax year after the year the penalty was imposed — the rate drops to 10%.⁶

Roth IRAs and designated Roth accounts within 401(k) or 403(b) plans are exempt from RMDs during the original owner’s lifetime.⁵ That distinction matters, because the exemption lets you choose when — and whether — to withdraw.

Your Money Is Locked Up Until 59½

Money inside a qualified retirement account is effectively frozen until age 59½. Distributions taken earlier generally trigger a 10% additional tax on top of the ordinary income tax you already owe.⁷ The combined bite can run 30% to 40% of an early withdrawal, which makes retirement accounts a poor source of emergency liquidity.

That is the opportunity cost of piling too much into tax-deferred savings. A regular brokerage account lets you sell at any time and pay the long-term capital gains rate — 0%, 15%, or 20% depending on income — on assets held more than a year. Retirement account distributions are always taxed as ordinary income. If you might need funds before 59½ for a business, a home, or an emergency, concentrating too much in retirement accounts leaves you without good options. Certain exceptions to the 10% penalty exist (separation from service at 55, first-time home purchase up to $10,000 from an IRA, large unreimbursed medical expenses, and substantially equal periodic payments), but they are narrow and none of them eliminate the underlying income tax.⁸

What Your Heirs Inherit With a Big IRA

A large retirement account is not just your tax problem. It becomes your beneficiary’s. Under the SECURE Act of 2019, most non-spouse beneficiaries — including adult children — who inherit a traditional IRA or 401(k) must empty the account within 10 years of the original owner’s death.⁹ Before that change, beneficiaries could stretch distributions across their own lifetimes and blunt the annual tax hit.

A narrow group of “eligible designated beneficiaries” — surviving spouses, minor children, disabled or chronically ill individuals, and beneficiaries not more than 10 years younger than the account owner — can still take distributions over their life expectancy.⁹ Everyone else has 10 years.

The practical effect is harsh. An adult child who inherits a $2 million traditional IRA during peak earning years might have to distribute $200,000 or more a year, all as ordinary income. Stacked on top of a salary, those distributions can push the heir into the 35% or 37% federal bracket. Add state income tax where retirement distributions are taxable, and 40% to 50% of the account can go to tax. Inherited IRAs do not receive a step-up in basis. Every dollar distributed is fully taxable, no matter when the original contributions were made.

Estate Tax at the High End

For very large balances, federal estate tax adds another layer. The 2026 estate tax exemption is $15,000,000 per person, so estates below that owe no federal estate tax.² Amounts above the exemption are taxed at a top rate of 40%. Married couples can effectively shield up to $30 million between them by using portability of the unused spouse’s exemption.

Retirement accounts are included in the taxable estate at their full balance. Unlike other inherited assets that receive a step-up in basis, traditional retirement accounts are counted in the estate for estate tax purposes and then fully taxed as ordinary income when the heir takes distributions. That double layer can dramatically reduce what the beneficiary actually keeps. Roughly a dozen states also impose their own estate or inheritance taxes, often with far lower exemption thresholds than the federal one.

How to Bring the Tax Bill Down

If you have already built a large tax-deferred balance, several strategies can reduce the long-term tax burden on you and your heirs.

Roth Conversions

A Roth conversion moves money from a traditional IRA or 401(k) into a Roth IRA. You pay ordinary income tax on the converted amount in the year of the conversion, but the money then grows and comes out tax-free in retirement. There is no income limit on conversions, so even high earners who cannot contribute directly to a Roth IRA can still convert.¹⁰ Roth accounts are also exempt from RMDs during your lifetime.⁵

Sizing matters. Converting too much in one year can push you into a higher bracket or trigger IRMAA. Many retirees convert smaller amounts across the low-income window between retirement and the start of Social Security or RMDs, filling up lower brackets without spilling into expensive ones.

Qualified Charitable Distributions

If you are 70½ or older, you can send up to $111,000 per year ($222,000 for married couples) directly from your IRA to a qualified charity. These qualified charitable distributions satisfy part or all of your RMD but are excluded from your taxable income entirely.¹⁰ If you already give to charity, a QCD is more tax-efficient than taking the distribution, paying tax on it, and then donating from after-tax money, even if you itemize.

Health Savings Accounts

If you are still working and enrolled in a high-deductible health plan, a Health Savings Account gives you a rare combination: deductible contributions, tax-free growth, and tax-free withdrawals for qualified medical expenses at any age. For 2026, the contribution limit is $4,400 for individual coverage and $8,750 for family coverage.¹¹ HSAs have no RMDs, and after age 65 you can withdraw for any purpose (paying ordinary income tax, similar to a traditional IRA, but without the penalty). Funding an HSA instead of piling more into pre-tax retirement accounts diversifies your future tax exposure.

Timing Distributions Before RMDs Force Your Hand

The years between retirement and age 73 are often a window of lower taxable income. Taking voluntary distributions from tax-deferred accounts during that window, even if you don’t need the cash, lets you fill lower brackets and shrink the balance before RMDs force larger withdrawals at potentially higher rates. Pairing this with Roth conversions is especially effective, since the converted funds will never generate RMDs. For retirees already taking RMDs, coordinating distributions with Social Security claiming decisions and capital gain harvesting can smooth taxable income across years rather than let it spike.

1
Internal Revenue Service. 401(k) Resource Guide Plan Participants General Distribution Rules
2
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
3
Internal Revenue Service. IRS Reminds Taxpayers Their Social Security Benefits May Be Taxable
4
Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
5
Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs
6
Office of the Law Revision Counsel. 26 USC 4974 – Excise Tax on Certain Accumulations in Qualified Retirement Plans
7
Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts – Section: 10-Percent Additional Tax for Early Distributions
8
Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions
9
Internal Revenue Service. Retirement Topics – Beneficiary
10
Internal Revenue Service. Retirement Plans FAQs Regarding IRAs Distributions (Withdrawals)
11
Internal Revenue Service. Expanded Availability of Health Savings Accounts Under the One, Big, Beautiful Bill Act