Additional Medicare Tax applies when your earned Medicare wages surpass a certain threshold based on your tax filing status. Your employer is responsible for withholding a 0.9% Additional Medicare Tax on your wages paid in excess of $200,000 in a calendar year, regardless of filing status. Your employer is obligated to begin withholding Additional Medicare Tax in the pay period in which it paid wages above $200,000 to you and will continue to withhold this amount each pay period until the end of the calendar year. There’s no employer match for Additional Medicare Tax.