Does MAGI include the 15% reduction to SS that makes AGI? Is this reduced amount considered as Non-taxable social security payments

Hi, @Earl22. MAGI has different calculations based on why it is being modified. So, for which purpose are you trying to determine MAGI?

Medicare brackets

According to the Social Security Administration , the only modification to AGI for determining Medicare Part B premiums is the addition of tax-exempt interest. So, no, the untaxed portion of your Social Security does not affect your Medicare premiums.