You've Heard of Uncle Sam. Have You Met Aunt IRMAA?
What a $4 Million Retirement Portfolio Really Needs to Do
Everyone knows Uncle Sam is going to take his cut. You've planned for taxes your whole working life. You get it.
But most high-net-worth retirees have never heard of Aunt IRMAA — and she can quietly cost a married couple $10,000 or more per year in Medicare surcharges they never saw coming. More on her in a moment.
First, let's talk about what a $4 million retirement portfolio actually needs to do — because generating a paycheck is only part of the job.
What a $4 Million Retirement Portfolio Needs to Do
1. Build a Downside Reserve First
Before anything else, set aside 2 to 2.5 years of income needs in cash, money market funds, or short-duration bonds — completely separate from your investment portfolio. This is your buffer. When markets drop, you live on this. Your equities stay invested and have time to recover.
At $4 million, this might mean $350,000–$450,000 parked safely. It costs you some return. It buys you something more valuable: the ability to stay the course when everyone else is panicking.
2. Understand Sequence of Returns Risk — Before It's Too Late
Here's the retirement risk nobody talks about enough: it's not just whether markets go down — it's when.
A 30% market drop in year two of retirement, combined with pulling income from that same portfolio, means you're selling shares at their lowest point. Those shares never recover for you — you already spent them. This is called sequence of returns risk, and it can permanently damage a retirement portfolio even if markets fully rebound.
The downside reserve in #1 above is your first defense. A disciplined rebalancing strategy is your second.
3. Meet Aunt IRMAA — She's Been Watching Your Tax Return
IRMAA stands for Income-Related Monthly Adjustment Amount. It's a Medicare surcharge that kicks in when your Modified Adjusted Gross Income (MAGI) exceeds certain thresholds — and at $4 million in retirement assets, there's a very good chance it applies to you.
2026 IRMAA thresholds:
- Married filing jointly: surcharge begins at $218,000 in MAGI
- Single filers: surcharge begins at $109,000 in MAGI
- At the highest tiers, a married couple can pay nearly $10,000 per year extra in Medicare premiums alone — for the exact same coverage as their neighbor
What makes IRMAA especially dangerous: it looks backward two years. Your 2026 Medicare premiums are based on your 2024 tax return. By the time the letter arrives from Social Security, you can't change anything. The income that triggered it is already history.
And the system is a cliff — cross a threshold by $1, and your premiums jump to the next tier. Entirely. Immediately. For the whole year.
A Roth conversion, a large capital gain, a big IRA distribution — any of these can quietly push you into a higher IRMAA bracket two years down the road if nobody is watching.
4. Generate Income — But Structure It Intelligently
A $4 million portfolio at a 4% withdrawal rate generates $160,000 per year. The question is: how much of that actually lands in your pocket?
The source of your income matters as much as the amount:
- Traditional IRA / 401(k) withdrawals — fully taxable as ordinary income; count toward IRMAA
- Roth IRA withdrawals — tax-free; do not count toward IRMAA
- Taxable brokerage — qualified dividends and long-term gains taxed at lower rates
- Social Security — up to 85% taxable depending on your total income level
The right withdrawal strategy blends these sources deliberately, year by year, with an eye on your tax bracket, your IRMAA tier, and your long-term plan.
5. Don't Forget Total Return — Growth Is Not Optional
Retirement isn't just about income. It's about not running out of purchasing power 25 years from now.
At 3% annual inflation, $100,000 in expenses today costs nearly $210,000 in 25 years. A portfolio built entirely around income — bonds, CDs, dividend stocks — with no meaningful growth component risks losing ground quietly, year after year.
We use a total return approach: income-generating assets for stability, and a disciplined equity allocation for long-term capital appreciation. The goal is a portfolio built to last as long as you do.
6. Tax-Loss Harvesting — Turning Market Dips Into Tax Savings
When individual positions in your portfolio decline, we can sell them to realize a loss — and use that loss to offset taxable gains elsewhere in your portfolio, or up to $3,000 of ordinary income per year. The proceeds are reinvested in a similar (but not identical) holding so your investment strategy stays intact.
Over time, disciplined tax-loss harvesting is one of the most consistent sources of "free" after-tax return in a well-managed portfolio. It doesn't show up on a performance statement. But it shows up in your pocket.
7. The Full Tax Toolkit: It's Not How Much You Make — It's How Much You Keep
This is where coordinated planning separates a good retirement from a great one. Here's what the toolkit looks like:
Roth Conversions: Convert traditional IRA dollars to Roth in lower-income years — especially the window between retirement and age 73 when Required Minimum Distributions begin. Every dollar converted now is a dollar that will never be subject to RMDs, IRMAA, or ordinary income tax again.
Qualified Charitable Distributions (QCDs): If you're charitably inclined and over age 70½, a QCD allows you to send up to $108,000 per year directly from your IRA to charity. It satisfies your RMD. It is excluded entirely from taxable income. It doesn't count toward IRMAA. For the right client, it's one of the most powerful tools in the tax code — and one of the most underused.
Capital Gains Harvesting: In years when income is low (often early retirement, before Social Security and RMDs stack up), you may be able to realize long-term capital gains at the 0% federal rate. That's income that would otherwise be taxed at 15–20% later. Harvesting it intentionally is a form of quiet tax arbitrage.
Strategic Withdrawal Sequencing: Which account do you draw from first? The answer isn't always "IRA." The right sequencing depends on your tax bracket, IRMAA exposure, Social Security timing, Roth conversion plan, and estate goals. Getting this wrong costs real money over a 25-year retirement.
Account Location: Which investments live in which accounts? Interest-generating bonds belong inside tax-deferred accounts. Tax-efficient equities belong in taxable accounts. Done right, this reduces annual tax drag without changing your overall investment strategy.
Social Security Timing: Every year you delay past full retirement age adds roughly 8% to your permanent benefit. For a couple where both spouses have meaningful earnings histories, the lifetime value of optimal Social Security timing can exceed $100,000. It also interacts with IRMAA, Roth conversion strategy, and RMD planning — which means it can't be decided in isolation.
Putting It All Together
Here's what a coordinated plan looks like for a couple at 67 with $4 million:
- Buffer: $400,000 in cash and short-duration bonds — 2.5 years of income needs, untouched by market swings
- Income: Blended from Social Security, IRA withdrawals, and taxable account distributions — sized to stay below IRMAA tier thresholds where possible
- Roth conversion program: Annual conversions filling the gap between current income and the next tax bracket ceiling — before RMDs make it harder
- QCD strategy: Charitable giving routed through the IRA to eliminate that income from MAGI entirely
- Tax-loss harvesting: Ongoing, systematic, embedded in portfolio management
- Growth allocation: Disciplined equity exposure, broadly diversified, designed to protect purchasing power over a 25-year horizon
None of this is set-it-and-forget-it. It's reviewed every year. Income levels shift. Tax law changes. Markets move. Life happens. The plan adjusts.
What Many Retirees Get Wrong
They focus on gross income, not net income. A $160,000 withdrawal that nets $105,000 after taxes is not the same as one structured to net $135,000. The math matters. The structure matters.
They discover IRMAA the hard way. A letter arrives. Medicare premiums have doubled. They had no idea the Roth conversion — or the capital gain — they took two years ago pushed them over the cliff. Now it's too late to fix it.
They don't have a buffer — and they sell when they shouldn't. Markets drop. Income needs don't pause. They sell equities at a discount to fund living expenses and permanently impair their portfolio's recovery.
They treat each decision in isolation. Roth conversion without checking IRMAA. Social Security timing without factoring in the Roth conversion window. Charitable giving from a brokerage account when a QCD would have been tax-free. Every one of these is a missed opportunity — and they compound.
They optimize for investment return and ignore tax drag. A great year in the market means nothing if a poorly structured plan gives half of it back to Uncle Sam — and Aunt IRMAA.
This Is Exactly What We Do at One Bridge
We work with high-net-worth families in the St. Louis area who have worked hard to build meaningful wealth — and who want to make sure it works just as hard for them in retirement. We're fiduciaries when managing your assets, and we bring a multifamily office approach to income planning, tax strategy, Medicare exposure, estate coordination, and investment management — all under one roof, all working together.
If you have a portfolio in the $2 million to $6 million range and want to see what a more coordinated plan might look like, we'd welcome the conversation.
Schedule a Complimentary Conversation
Frequently Asked Questions
What is IRMAA and how does it affect retirees with substantial assets?
IRMAA (Income-Related Monthly Adjustment Amount) is a Medicare surcharge for higher-income retirees. In 2026, it begins at $109,000 MAGI for single filers and $218,000 for married couples filing jointly. Because it uses a two-year lookback, decisions made today — Roth conversions, capital gains, large IRA withdrawals — affect Medicare premiums two years from now. At the highest income tiers, a married couple can pay close to $10,000 more per year in Medicare premiums for the same coverage as someone just below the threshold.
What is sequence of returns risk and why does it matter at retirement?
Sequence of returns risk is the danger of experiencing poor market returns early in retirement while simultaneously drawing income from your portfolio. Selling investments at depressed prices to fund living expenses locks in losses permanently. A 2 to 2.5 year cash and short-term bond buffer allows you to meet income needs during downturns without touching your equity positions.
What is a Qualified Charitable Distribution and who benefits most?
A QCD is a direct transfer from your IRA to a qualified charity, available to IRA owners age 70½ and older. Up to $108,000 per year can be transferred tax-free, satisfying your Required Minimum Distribution without the distribution appearing in your taxable income — keeping it out of IRMAA calculations and reducing Social Security taxation. It is one of the most tax-efficient tools available to charitably inclined retirees.
When is the best time to do Roth conversions?
The best window is typically between retirement and age 73, before Required Minimum Distributions begin. During this period, income is often temporarily lower, making conversions more tax-efficient. Conversions should be sized carefully each year to stay below IRMAA tier thresholds and tax bracket ceilings — requiring coordination with Social Security timing, planned withdrawals, and charitable giving strategy.
How does tax-loss harvesting work in a retirement portfolio?
Tax-loss harvesting involves selling investments that have declined in value to realize a tax loss, which can offset capital gains or up to $3,000 of ordinary income per year. The proceeds are reinvested in a similar holding to maintain portfolio exposure. Done systematically, it is one of the most consistent sources of additional after-tax return in a well-managed portfolio.
One Bridge Wealth Management does not offer tax advice. You should consult a tax professional regarding your individual situation.