I was looking over DH's W-2 form for 2012 and compared it to 2011. He made $700 more in 2012 but contributed $80 less to 401k so a net of $620 more in 2012. He hasn't changed his withholding in many years but although he made more money in 2012, he had $827 less in Federal taxes withheld. His state taxes are correct(haven't done the taxes yet but percent wise). He spoke to the lady in the office (no HR dept) and she has no answer but confirmed his with-holdings were the same. Any ideas why the difference? Edited to add for clarification... In 2012, he made $620 more before 401k but his income after the 401k deductions in 2012 was $700 more.(he contributed $80 more in 2011 than he did in 2012. He must have had 53 paychecks in 2011) The only other things deducted from his check are uniforms (they were $200 less in 2012) and union dues (they were $30 more in 2012). He does not have insurance withheld from his pay.