The Treasury Department on Thursday released the withholding tables for the new tax law.
The tables lay out how much tax to withhold or not withhold from paychecks. With these new guidelines, companies can start adjusting employee paychecks.
While employers can begin doing this voluntarily, they will have to comply with the new guidance by Feb. 15.
Treasury Secretary Steven Mnuchin said the government expects about 90 percent of workers to see an increase in their take-home pay.
Later Thursday, Mnuchin said that the guidance is not an attempt by the administration to boost paychecks before the midterm elections in the fall. He said the IRS issues tables every January.
"Any claims that we're doing this for political issues are ridiculous," he told reporters at the White House's daily press briefing.
The Treasury also said that employers should withhold 22 percent for taxes on bonuses — lower than the current rate of 25 percent. This rate would apply to the special bonuses distributed following the passage of the tax overhaul.
The government said that workers will not have to fill out new W-4 forms to take advantage of the changes this year.
But the Internal Revenue Service said it is working on a new W-4 form, which a significant number of workers will have to fill out in order to benefit from the changes in 2019.