What happened was that the Government changed the withholding tables to withhold less pay from people's paychecks; however, depending on how much on makes and one's specific tax situation, this can lead to one having insufficient tax withheld. Before I did any adjustment, my paycheck did go up a bit -- not as part of any raise, but simply because less tax was withheld. After doing the calculation and refiling my W-4, the net pay went back down, although it was still slightly more than what I'd been taking home before.