In 2003, the Jobs and Growth Tax Relief Reconciliation Act was put into effect to put more money into employees paychecks. This required the IRS to develop a new tax table and must be used by employers as of July 2003. Now as a result of the American Recovery and Reinvestment Act of 2009, these tables have once again been revised. This new act provides more money for the employee on a weekly basis by lowering the amount of federal tax liability. Learn More, http://hubpages.com/hub/Federal-Payroll-Tax-Withholding-Table-for-2009--2010