Followings are the main changes:
1) For Year 2011, the employee tax rate for social security is reduced to 4.2%. The employer tax rate for social security remains unchanged at 6.2%. (IRS asks that employers start using the new social security rate as soon as possible but not later than January 31, 2011.)
2) Federal payroll tax table changed
Click here to compare Year 2011 Federal tax tables and Year 2010 Federal tax tables
3) State table changed
IL, CO, HI, IN,ME, MD, MN, MO, NM, ND, OK, RI, VT published the new state tax tables.