What Is an IRMAA in Medicare?

• An IRMAA is a surcharge added to your monthly Medicare Part B and Part D premiums, based on your yearly income.
• The Social Security Administration (SSA) uses your income tax information from 2 years ago to determine if you owe an IRMAA in addition to your monthly premium.
• The surcharge amount you’ll pay depends on factors like your income bracket and how you’ve filed your taxes.
• IRMAA decisions can be appealed if there’s an error in the tax information used or if you’ve experienced a life changing event that reduced your income.

Many parts of Medicare involve paying a monthly premium. In some cases, your monthly premium may be adjusted based on your income. One such case might be an income-related monthly adjustment amount (IRMAA). IRMAA applies to Medicare beneficiaries who have higher incomes. Keep reading to learn more about IRMAA, how it works, and the parts of Medicare that it applies to.

What is an IRMAA?

The Social Security Administration (SSA) determines your IRMAA. This is based on information provided by the Internal Revenue Service (IRS). You could receive a notice from the SSA regarding an IRMAA at any time of the year. If the SSA decides that an IRMAA applies to your Medicare premiums, you’ll receive a predetermination notice in the mail. This will inform you about your specific IRMAA and will also include information such as:

• how the IRMAA was calculated
• what to do if the information used to calculate the IRMAA is incorrect
• what to do if you had a reduction in income or a life changing event

You’ll then receive an initial determination notice in the mail 20 days or more after getting the predetermination notice. This will include information about the IRMAA, when it goes into effect, and steps that you can take to appeal it.

You won’t have to take any additional action to pay the surcharges associated with the IRMAA. They will be automatically added to your premium bills.

Each year, the SSA reevaluates whether an IRMAA should apply to your Medicare premiums. So, depending on your income, an IRMAA could be added, updated, or removed.

What parts of Medicare does IRMAA affect?

​Medicare Part A

​Part A is hospital insurance. It covers inpatient stays at locations such as hospitals, skilled nursing facilities, and mental health facilities. IRMAA doesn’t affect Part A. In fact, most people who have Part A don’t even pay a monthly premium for it.

Medicare Part B

​Part B is medical insurance. It covers:

• various outpatient health services
• durable medical equipment
• some types of preventive care

An IRMAA can affect your Part B premium cost. Based on your annual income, a surcharge can be added to the standard Part B premium.

Medicare Part C

Part C is also referred to as Medicare Advantage. These plans often cover services that original Medicare (parts A and B) don’t cover, such as dental, vision, and hearing.
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Part C is not affected by IRMAA.

Medicare Part D

​Part D is prescription drug coverage. Like Part C plans, Part D plans are sold by private companies.

Part D is affected by IRMAA. As with Part B, a surcharge can be added to your monthly premium, based on your yearly income. This is separate from the surcharge that can be added to Part B premiums.