You may already be familiar with IRMAA. I’m not the Irma who lives on your street. I am referring to the Part D income-related monthly adjustment amount (IRMAA).

Individuals with Medicare who pay a higher Part B premium because their modified adjusted gross income is above the threshold (i.e., more than $85,000 for an individual and $170,000 for a married couple) also have to pay a slightly higher portion of their Medicare Part D plan premium. This surcharge to Part D is IRMAA, and less than 5% of the Medicare population is affected by it.

The Part D IRMAA is calculated and based on a percentage of the Part D national base beneficiary premium amount. The Part D IRMAA for 2018 will be slightly lower than that of 2017. In 2018, those with higher incomes will pay (in addition to their Part D premium) the following based on their annual income:

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• $0.00 (individual income of $85,000 or less; joint income of $170,000 or less)

• $13.00 (individual income between $85,001- $107,000; joint income between $170,001-$214,000)

• $33.60 (individual income between $107,001-$133,500; joint income between $214,001-$267,000)

• $54.20 (individual income between $133,501- $160,000; joint income between $267,001-$320,000)

• $74.80 (individual income above $160,000; joint income above $320,000)

Medicare Part D beneficiaries affected by the 2018 IRMAA will receive a letter from the Social Security Administration notifying them of their Medicare Part D plan premium increase. The amount of your IRMAA will be directly deducted from your Social Security, Railroad Retirement Board, or Office of Personnel Management benefits. If there are not sufficient funds in your government benefits, then Medicare will bill you directly. If you do not pay your IRMAA, you will be involuntarily disenrolled from your Medicare Part D or Medicare Advantage plan and may be without Medicare plan coverage for the remainder of the year.

It’s also important to note that the IRMAA charge is based on the prior year income. So if your income decreases in the current year, your IRMAA charge will not lower until the following year.