FICA
Also called: Federal Insurance Contributions Act, Social Security tax, Medicare tax
FICA is the US payroll tax funding Social Security and Medicare — 6.2% and 1.45% from you, matched by your employer. The Social Security portion stops above an annual wage cap, which is why high earners see their take-home pay rise late in the year, while the Medicare portion has no cap and gains a surtax above a threshold. It's levied on gross wages before most deductions, so it's the tax hardest to plan around.