The IRS has announced that it is revising Form W-4 and its online withholding tax calculator. The revisions will reflect changes made by the Tax Cuts and Jobs Act. Until a new Form W-4 is issued, the 2017 Form W-4 should be used. The IRS expects the revised tax calculator to be available by the end of February. For 2019, the IRS anticipates making further changes involving withholding and will work with the business and payroll communities to encourage employees to file new Forms W-4 next year.