
Starting in 2019, there will be a new Income Related Monthly Adjustment Amount (IRMAA) tier for Medicare Part B premium surcharges for individuals earning more than $500,000 (or married couples with AGI in excess of $750,000), stacked on top of what were additional adjustments to the Medicare premium surcharge tiers that just took effect in 2018.
Since 2006, the Medicare Modernization Act has required that certain “high-income” individuals pay an IRMAA as a surcharge on their Medicare Part B premiums. In 2018, the surcharge started at an extra $53.50/month, and could rise as high as an extra $294.60/month on Medicare Part B, and applied to those whose (Modified) Adjusted Gross Income exceeded $85,000 (for individuals, or a MAGI above $170,000 for married couples). The end result of these IRMAA surcharges increased the total percentage of Part B costs that are covered by premiums, from 25% (the amount covered by the base $134/month Medicare Part B premium) to as high as 80% (for those paying the full $134 + $294.60 = $428.60/month premium).