The Medicare tax rate is 1.45% for the employer and employee each. For the Additional Medicare Tax, the income threshold is $200,000, at which point the 0.9% above that amount is withheld from the employees' income.

An employer must withhold Additional Medicare Tax from wages it pays to an individual in excess of $200,000 in a calendar year, without regard to the individual’s filing status or wages paid by another employer.

Your employer must withhold Additional Medicare Tax on wages it pays to you in excess of $200,000 in a calendar year. Your employer cannot honor a request to cease withholding Additional Medicare Tax if it is required to withhold it. You will claim credit for any withheld Additional Medicare Tax against the total tax liability shown on your individual income tax return (Form 1040 or 1040-SR).

An employee can credit any withheld additional Medicare tax against the total tax liability shown on his income tax return by filing Form 8959, Additional Medicare Tax, with Form 1040.

If you owe this tax, file Form 8959, with your tax return.