Medicare IRMAA Explained: Who Pays and How to Appeal

If you opened a letter from Social Security saying your Medicare premiums will be higher because of your income, you have met IRMAA. It surprises a lot of people, especially those who just retired and are being charged based on income they no longer earn. This guide explains what IRMAA is, how Social Security decides who pays it, why the two-year lookback catches new retirees, how to ask for a new decision after a life-changing event using Form SSA-44, and what an insurance agent can and cannot do about it.

Key takeaways

• IRMAA is an extra amount added to your Part B premium and your Part D premium if your income is above a threshold set each year.
• Social Security uses your modified adjusted gross income from the tax return the IRS most recently provided, usually from two years earlier.
• If your income dropped because of a life-changing event such as retirement, you can ask Social Security for a new determination using Form SSA-44.
• The brackets and amounts change every year. Get the current numbers from Medicare.gov or ssa.gov, not from a memory or a forum post.
• Switching plans does not change IRMAA. It is set by Social Security, not by your insurer, so an agent can explain it but cannot reduce it.

What IRMAA is

Most people pay the standard Part B premium, and the federal government pays the larger share of the true cost of Part B. Federal law requires people with higher incomes to pay a larger share of that cost. The extra amount is the income-related monthly adjustment amount, or IRMAA.

There are two IRMAAs:

• Part B IRMAA is added to your Part B premium.
• Part D IRMAA is added on top of whatever your drug plan charges. It applies whether you have a standalone Part D plan or a Medicare Advantage plan with drug coverage, and it applies even if your plan's own premium is zero.

Both are set on a sliding scale with several income tiers. The higher your income, the larger the adjustment. Only a minority of people with Medicare pay IRMAA, and the law does not apply to you at all if your income is below the first threshold.

How Social Security decides

Social Security, not Medicare and not your insurance company, makes the IRMAA determination. The process works like this:

1. The IRS provides Social Security with income information from your most recent federal tax return on file.
2. Social Security calculates your modified adjusted gross income (MAGI). For IRMAA, MAGI is your adjusted gross income plus any tax-exempt interest income.
3. Social Security compares your MAGI to the thresholds for your tax filing status. Married couples filing jointly have different thresholds from single filers, and people who are married but file separately face their own rules.
4. If your MAGI is above the first threshold, Social Security sends you an initial determination letter stating your premium amounts and the reason.

If you receive Social Security benefits, IRMAA is deducted from your monthly payment. If you do not, or the amount exceeds your benefit, you are billed separately. Part D IRMAA is paid to Medicare, not to your drug plan, even though it is tied to drug coverage.

The two-year lookback

The part of IRMAA that surprises new retirees is timing. Because Social Security uses the most recent tax return the IRS has provided, there is a built-in delay.

That means the income you earn in your final full year of work can drive your Medicare premiums two years later, after you have retired and your income has fallen. Social Security's rules anticipate this, which is why the life-changing event process exists.

Occasionally the IRS provides an older return. If Social Security used a return from three years ago and you have since filed a more recent one, you can ask Social Security to update its records.

Income events that commonly trigger IRMAA

Because MAGI includes most taxable income, one-time events can push you over a threshold for a single year:

• Selling a home, if the gain exceeds the exclusion for a primary residence
• Selling investments or a business with a large capital gain
• Converting a traditional IRA to a Roth IRA
• Required minimum distributions from retirement accounts
• A severance package, deferred compensation, or a final year of high earnings before retirement
• Tax-exempt municipal bond interest, which is added back for IRMAA even though it is not taxed

Whether and how to manage these is a question for a tax professional or financial advisor. The point here is to recognize that a large one-year income spike typically produces a one-year IRMAA, and that the adjustment is recalculated every year.

Life-changing events and Form SSA-44

Social Security will consider a new determination if a life-changing event reduced your income. The events it recognizes are:

• Marriage
• Divorce or annulment
• Death of a spouse
• Work stoppage, such as retirement
• Work reduction, such as moving to part-time hours
• Loss of income-producing property because of a disaster or other event beyond your control
• Loss of pension income because an employer's pension plan ended or was reorganized
• An employer settlement payment because of the employer's closure, bankruptcy, or reorganization

To request a new determination, complete Form SSA-44, Medicare Income-Related Monthly Adjustment Amount - Life-Changing Event, or contact Social Security directly. You will be asked for:

• The type and date of the event
• Your estimated MAGI for the year the event affects, and sometimes the following year
• Documentation, such as a letter from your employer confirming retirement, a death certificate, or a divorce decree

You can submit the form by mail, in person at a Social Security office, or by phone appointment. Social Security recommends providing a signed copy of your tax return for the affected year once it is filed, so it can finalize the decision.

Two other situations use different paths:

• The tax information was wrong or you filed an amended return. Contact Social Security with a copy of the amended return and the IRS acknowledgment. This is a correction, not a life-changing event.
• You simply disagree with the determination. You can request a reconsideration. The letter you received explains the deadline, which is generally 60 days from when you received it.

What IRMAA is not

Clearing up a few misunderstandings saves people time and frustration:

• It is not a plan premium. IRMAA is charged by the government based on your income. Changing Medicare Advantage plans, Part D plans, or Medigap companies does not change it.
• It is not permanent. It is recalculated every year from the newest tax return. One high-income year usually means one year of IRMAA.
• It is not avoided by skipping Part D. If you have no drug coverage, you do not pay Part D IRMAA, but you also risk the Part D late enrollment penalty and the cost of prescriptions.
• It is not applied to Part A. Most people pay no Part A premium, and IRMAA does not affect it.
• It is not calculated per household. Each spouse on Medicare receives their own determination, although a joint return sets both.

An agent's role versus Social Security's

A licensed Medicare agent can help you understand an IRMAA letter, explain how Part D IRMAA interacts with the plan you are choosing, and make sure you do not drop drug coverage in a way that triggers a penalty. Agents can also help you compare plans in a year when your total Medicare costs are higher than expected.

What an agent cannot do is change the amount. Only Social Security can issue, correct, or reverse an IRMAA determination. Questions about reducing future MAGI through the timing of withdrawals, conversions, or sales belong with a tax professional or financial advisor. If someone selling insurance claims they can eliminate IRMAA by moving you to a different plan, that is a sign to be careful.

Agents are paid by the carriers, so their help with plan choices does not add to your premium. Verify their license before you share your Medicare number. Texans can browse Medicare agents in Texas or read our Medicare in Texas guide.

If you receive an IRMAA letter: a short checklist

1. Read which tax year Social Security used and confirm the income figures match your return.
2. If you have filed a more recent return that shows lower income, contact Social Security to update the record.
3. If a life-changing event reduced your income, complete Form SSA-44 with documentation.
4. Note the deadline for requesting a reconsideration if you disagree.
5. Check the current thresholds on Medicare.gov or ssa.gov to understand which tier you are in and what a lower estimate would change.
6. Keep your drug coverage; do not drop Part D to avoid Part D IRMAA without understanding the penalty.

Our turning 65 Medicare checklist includes IRMAA planning in the months before enrollment, and how to compare Medicare Part D plans explains the late enrollment penalty in detail.

Talk to a licensed agent for free

Medicare agents are paid by the insurance carriers whose plans they sell, so you pay nothing extra for their time, and your premium is the same either way. A licensed agent can explain how IRMAA fits into your total Medicare costs, compare Medicare Advantage, Medigap, and Part D plans, and help you enroll before the deadline. When you are ready, you can find a licensed health insurance agent near you and get connected at no cost.