Why Did My Medicare Premium Go Up? (IRMAA Explained Simply)

If no one clearly explained why your Medicare premium went up, you’re not alone.

This is one of the most common (and frustrating) situations I see.

And here’s the part that surprises most people:

Your Medicare premium is based on your income from two years ago.

You didn’t change your plan.

Your benefits didn’t change.

But suddenly… your monthly cost did.

And in most cases, it comes down to something called IRMAA—an income-related surcharge that affects Medicare Part B and Part D premiums.

Let me break this down in plain English—because once you understand it, you can actually plan around it.

The Real Reason — It’s Not Random

What you’re seeing is called an Income-Related Monthly Adjustment Amount, often shortened to IRMAA.

IRMAA is an extra charge added to your:

• Medicare Part B premium
• Medicare Part D drug plan premium

And here’s the part most people don’t realize:

Your IRMAA amount is usually based on your income from two years ago.

So, for example:

• Your 2026 IRMAA amount is generally based on your 2024 tax return.

That’s why it can feel like it came out of nowhere.

What Is IRMAA?

IRMAA is an extra amount added to Medicare Part B and Part D premiums for people whose income is above certain limits.

If you’re not familiar with how IRMAA works, here’s a full breakdown.

The 3 Most Common Triggers

IRMAA is often triggered by income that people do not realize will affect their Medicare premiums. Here are three common reasons it happens.

1. You Had a Higher-Income Year, Even Temporarily

This could include:

• Selling a home or property
• Taking a large IRA or 401(k) withdrawal
• Capital gains from investments

Even if it was a one-time income spike, Medicare may still use that tax return when calculating your IRMAA amount.

Medicare rules can also change based on certain life situations. For example, some people qualify for Medicare earlier than expected due to specific conditions. Here’s how ALS can affect Medicare eligibility and coverage .

2. You Went Back to Work

Here’s where people get confused:

• Your Social Security check usually is not reduced after full retirement age
• But your Medicare premiums may increase if your income rises

Why? Because higher income can move you into a higher IRMAA tier.

3. “Invisible Income” Most People Forget About

This may include:

• IRA or 401(k) withdrawals
• Tax-free municipal bond interest
• Dividends and capital gains

That income may count toward the Medicare income calculation used for IRMAA.

If you want to plan ahead and avoid this, download my IRMAA Survival Guide.

The $1 Problem: Where IRMAA Gets Expensive

Medicare uses income brackets to determine whether IRMAA applies.

That means if your income goes even slightly over a threshold, your Medicare Part B and Part D premiums may increase.

Even a small income increase can sometimes move you into a higher IRMAA tier.

That can mean:

• Higher monthly Medicare costs
• More money coming out of your Social Security check
• A surprise bill you were not expecting

And unfortunately, many people do not realize this until the premium increase has already happened.

You can estimate your IRMAA here before it catches you by surprise.

What You Can Do About It

This is where you may have more control than you think.

1. Plan Withdrawals Strategically

If possible, avoid taking large retirement account distributions all at once without understanding how they may affect your Medicare premiums.

Spreading withdrawals across tax years may help some people avoid moving into a higher IRMAA tier.

2. Be Mindful of “Spike Years”

IRMAA issues often show up after a higher-income year. This may happen if you are:

• Selling assets
• Converting money to a Roth IRA
• Taking large investment gains
• Withdrawing from retirement accounts

Those decisions may be smart financially, but they can also affect your future Medicare costs.

3. You May Be Able to Appeal IRMAA

If your income dropped because of a qualifying life-changing event, you may be able to file an IRMAA appeal using Form SSA-44.

Common life-changing events may include:

• Retirement
• Work reduction
• Marriage
• Divorce or annulment
• Death of a spouse
• Loss of pension income
• Loss of income-producing property

If approved, an appeal may reduce your IRMAA amount and lower your Medicare premiums.

What Most People Wish They Knew Earlier

This is the part I hear all the time:

“If I had known this, I would have planned differently.”

And that is exactly why I talk about IRMAA so much.

Because this is not just about choosing the “right” Medicare plan.

It is about understanding how your income, timing, and financial decisions may affect your Medicare costs.

If you prefer to see this explained visually, you can watch my free Medicare videos here.

If your premium went up and you are not sure why, or you want to avoid this happening again, you can book a Medicare review here.

No call centers. No pressure.
Just clear answers so you can make the right decision for you.

You can also explore my Medicare resources here to better understand your options.