Medicare beneficiaries with modified adjusted gross income (MAGI) over a set amount ($85,000 for single individuals and $170,000 for married persons filing jointly) pay an additional Part B and Part D premium. MAGI in 2017 is what is used to determine whether there’s an additional premium in 2019. MAGI for this purpose means your adjusted gross income plus tax-exempt interest income.
Tax paid by self-employed persons to finance Social Security coverage. In 2007, there are two rates. A 12.4% rate applies to a taxable earnings base of $95,700 or less and a 2.9% rate applies to all net earnings.