The Reality of Supplemental Income
Getting a $10,000 end-of-year corporate bonus sounds amazing, until your bank app shows a deposit of only $6,100. The IRS absolutely obliterates bonus payments because they classify them as "Supplemental Wages," triggering an entirely different, incredibly harsh withholding bracket than your standard bi-weekly paycheck.
The Taxation Mechanics
The 22% Flat Federal Levy
In the United States, employers typically use the "Percentage Method" for bonuses under $1 Million. They are legally required to withhold a massive, flat 22% upfront for federal taxes, regardless of your normal tax bracket.
FICA and Medicare
The bonus does not escape payroll taxes. You will universally lose an additional 7.65% immediately to Social Security and Medicare before any state taxes are even applied.
State Aggression
Many states (like California or New York) apply their own brutal supplemental withholding rates on top of the 22% federal rate, easily pushing the total tax drag well past 40%.