How Does IRMAA Affect When You Should Claim Social Security?

If you’re nearing retirement after years of earning a higher income, deciding when to claim Social Security isn’t as simple as comparing benefit amounts at different ages. 

One cost that’s easy to overlook is the Income-Related Monthly Adjustment Amount, better known as IRMAA. It’s an additional amount you may pay for Medicare Part B and Part D when your income exceeds certain thresholds.

IRMAA can turn your Social Security decision into a much broader retirement-planning conversation.

At Winthrop Partners, our fiduciary financial advisors view Social Security and Medicare decisions as connected parts of your retirement income plan. 

It’s important to note that there is no universally correct age for claiming. The appropriate timing depends on your cash-flow needs, health, longevity expectations, marital situation, tax exposure, investment accounts, and future income, which we’ll explore in more detail. 

Read our newest Quick Guide “How Does Evidence-Based Investment Management Help Retirees?”

What Is IRMAA, and How Does It Affect Medicare Premiums?

IRMAA is an income-based surcharge added to Medicare Part B and Part D premiums. Social Security generally determines your surcharge based on your modified adjusted gross income from two years earlier. Higher income can move you into one of several IRMAA tiers.

Think of IRMAA as a rearview mirror: Medicare usually prices today’s coverage by looking at income from two years earlier. This can create a surprise when you retire. 

Suppose you leave a highly compensated position at 65. Your current income may fall sharply, but Medicare could initially calculate IRMAA using the salary, bonus, or equity compensation you received while working.

For Medicare purposes, modified adjusted gross income, or MAGI, generally consists of your adjusted gross income plus tax-exempt interest. It can include income from:

• Wages and self-employment
• Pensions
• Taxable Social Security benefits
• Traditional IRA and 401(k) distributions
• Roth conversions
• Capital gains, dividends, and interest
• Rental or business income
• Tax-exempt municipal-bond interest

This list matters because IRMAA is based on more than the amount you spend. Taking money from one account rather than another can produce a different Medicare result, even when your lifestyle remains unchanged.

Watch: “What is the Best Age to Retire? How to Create a Retirement Window”

What Are the 2026 IRMAA Income Thresholds?

The table below shows how your 2024 modified adjusted gross income, or MAGI, can affect your 2026 Medicare costs. Your Part D IRMAA is added to the premium your prescription drug plan charges.

These thresholds work more like steps than a gradual slope. If your MAGI moves into the next tier, the corresponding premium generally applies for the year. For a married couple in which both spouses are enrolled in Medicare, the higher Part B premium and Part D adjustment may apply to each spouse.

The thresholds and premiums can change annually.

For example, before making a Roth conversion, realizing a large capital gain, or taking an additional retirement-account distribution, review the figures for the Medicare year your income may affect with an experienced CFP ® from Winthop Partners. 

Source: Social Security Administration—2026 Medicare premiums. The table applies to individual filers and married couples filing jointly; separate rules apply to certain married people filing separately.

Should You Delay Social Security to Reduce IRMAA?

Delaying Social Security may create a lower-income planning window, but it doesn’t always reduce IRMAA. You must compare the delayed benefit, required portfolio withdrawals, taxes, Medicare premiums, and longevity considerations together.

You can begin collecting Social Security retirement benefits as early as age 62, but doing so will permanently reduce your monthly payment. If you were born in 1943 or later, waiting beyond your full retirement age increases your benefit through delayed retirement credits of approximately 8% per year until age 70.

Waiting can be especially relevant when you are the higher earner in a married couple because the larger benefit may later influence the survivor benefit. But waiting also means funding more of your early retirement spending from other sources.

Consider a hypothetical couple retiring at 65 with significant traditional IRA savings. They plan to delay the higher earner’s Social Security benefit until 70. During those five years, they could evaluate measured Roth conversions or withdrawals before required minimum distributions begin. A conversion may create an IRMAA surcharge two years later, but that doesn’t necessarily make it a poor decision. 

Paying a temporary surcharge could accompany a strategy aimed at reducing later taxable balances. Conversely, converting too much at once may create federal and state taxes, higher Medicare premiums, or other unintended effects.

Remember that IRMAA is one cost in the Social Security equation, not the entire equation.

Check out our short video on: “Have You Saved $1 Million for Retirement? Here is Your Next Move.”

How Can You Coordinate Social Security and IRMAA Planning?

At Winthrop Partners, we help you examine these decisions across multiple years. That perspective matters because optimizing a single calendar year can lead to higher costs later.

We recommend building a year-by-year income map from your final working years through at least age 75. Include your projected wages, Social Security, pensions, required minimum distributions, investment income, planned asset sales, and possible Roth conversions.

Then compare each Social Security strategy using four lenses:

1. What monthly and survivor benefits could it provide?
2. How much would you need to withdraw from your portfolio while waiting?
3. How might it affect taxes and Medicare premiums?
4. What happens if you or your spouse lives longer, or not as long as expected?

Our comprehensive retirement planning process typically includes:

• Modeling several Social Security dates. Compare claiming at 62, full retirement age of 67, or at 70 based on expected spending, longevity, survivor needs, and portfolio withdrawals.
• Projecting MAGI before Medicare. Income earned at 63 can influence Medicare premiums at 65, making the years before enrollment part of the planning window.
• Testing Roth conversion ranges. Rather than assuming that more or less conversion is preferable, compare potential tax and IRMAA effects across several years.
• Managing investment gains. Capital-gain realization, concentrated-stock sales, and business transactions may require coordination with retirement-account distributions.
• Evaluating charitable strategies. Once eligible, qualified charitable distributions may satisfy part of an RMD without adding the distribution to adjusted gross income when the rules are followed.
• Planning for unexpected income. A bonus, mutual-fund distribution, property sale, or consulting project can narrow your distance from the next IRMAA tier.

These actions aren’t about keeping your income artificially low at any cost. They are about understanding tradeoffs before an irreversible decision is made.

Our role is to help you see how the pieces interact and evaluate alternatives in the context of your life, not to reduce a complex retirement decision to one claiming-age rule. Schedule a complimentary conversation with our team today about your Social Security and retirement planning needs. 

Frequently Asked Questions About IRMAA and Social Security

Does IRMAA apply to Social Security benefits?

IRMAA increases what you pay for Medicare Part B and Part D; it doesn’t reduce your Social Security benefit itself. However, if your Medicare premiums are deducted from your Social Security payment, the additional IRMAA charge can lower the amount deposited into your account each month.

What income counts toward IRMAA?

IRMAA generally uses adjusted gross income plus tax-exempt interest. Wages, pensions, taxable Social Security, traditional retirement account distributions, Roth conversions, capital gains, dividends, rental income, and municipal bond interest may count.

Can I ask Social Security to reconsider IRMAA after I retire?

Yes. If retirement, a reduction in work hours, or another qualifying life-changing event causes your income to decrease, you can ask Social Security to recalculate your IRMAA using more recent income information. You will generally need to submit Form SSA-44 along with documentation showing the qualifying event and your expected reduction in income.

Does delaying Social Security until 70 avoid IRMAA?

Not necessarily. Delaying removes Social Security income during the waiting period, but wages, withdrawals, conversions, investment gains, and other income may still trigger IRMAA.

Do Roth IRA withdrawals count toward IRMAA?

Qualified Roth IRA distributions generally do not enter MAGI. A Roth conversion does increase taxable income in the conversion year and may affect IRMAA two years later.

Can IRMAA change every year?

Yes. Social Security reevaluates IRMAA annually using available tax information, while the income thresholds and premium amounts can also change from year to year.

Should I take Social Security at 65 when I enroll in Medicare?

Medicare enrollment and Social Security claiming are separate decisions. You can enroll in Medicare at 65 while delaying Social Security, subject to the enrollment rules that apply to your employer coverage and circumstances.