The Medicare Income-Related Monthly Adjustment Amount (IRMAA) is an amount you may have to pay in addition to your Part B or Part D premium if your income is above a certain level. The Social Security Administration (SSA) sets four income brackets that determine your (or your and your spouse’s) IRMAA. SSA determines if you owe an IRMAA based on the income you reported on your IRS tax return two years prior, meaning two years before the year in which you are paying IRMAA. The income that counts is the adjusted gross income you reported plus other forms of tax-exempt income.
Your additional premium is a percentage of the national base beneficiary premium $35.02 in 2018. If you are expected to pay IRMAA, SSA will notify you that you have a higher Part D premium.
For 2018, your additional premium based on income is as follows:
| Individuals | Couples | What you pay in addition to your regular Part D premium |
| Equal to or below $85,000 |
Equal to or below $170,000 |
$0 |
| $85,001 – $107,000 | $170,001 – $214,000 | $13.00 |
| $107,001 – $133,500 | $214,001 – $267,000 | $33.60 |
| $133,501 – $160,000 | $267,001 – $320,000 | $54.20 |
| Above $160,000 | Above $320,000 | $74.80 |
If you believe you should not pay IRMAA, your circumstances have changed, or your IRMAA was miscalculated, you have the right to request that SSA lower or eliminate your premium increase. You will have to submit evidence if you are appealing SSA’s original determination or requesting a new determination.
Note: IRMAA is always calculated using the national base beneficiary premium. Your IRMAA will not decrease if you enroll in a Part D plan with a lower premium.