Additional Medicare tax calculator

The tax is 0.9 percent of $50,000, not of $250,000. That is $450, which is a very different number from 0.9 percent of the whole wage. The threshold works like a bracket boundary: everything under it is untouched.

The rate also stacks rather than replaces. Regular Medicare tax still applies to all wages, and this sits on top of it for the part above the line. How FICA works covers the base layer.

Regular Medicare tax is split between employee and employer. This one is not: the whole 0.9 percent falls on the employee. That makes it unusual among payroll taxes and it is why the figure appears on a payslip without a matching employer line.

For self employed people the same logic applies to net earnings above the threshold, on top of the ordinary self employment tax the self employment tax calculator computes.

An employer withholds this tax once wages from that job pass a single set level, because the employer only sees one job. The threshold that actually applies depends on filing status and total household wages, so two earners each below the level can still owe it jointly, and one job over the level can withhold more than is finally due.

That is why this calculator takes the threshold as an input. The second example runs $300,000 of wages against a $250,000 threshold, which is the joint filer shape, and produces the same $50,000 of excess and $450 of tax.

One wage figure, one threshold, one rate. It sizes the additional Medicare line and nothing else: income tax, Social Security and the ordinary Medicare rate are separate calculations on the same paycheque. The paycheck calculator puts the deductions together, and net pay is what survives them. This is educational material, not financial advice.