Although the Tax Cuts & Jobs Act has significantly changed the federal tax code, the Montana Department of Revenue has not announced any major reform. Many employers have recently requested employees to complete the new 2018 W-4 but if you've made changes in your withholding allowances to reflect federal tax changes, it could have an undesirable impact on your state withholding. The below is information from the MT Dept of Revenue website with advice to employees and employers for handling MT income tax withholding. We recommend that employees continue to use the number of allowances calculated on their 2017 (or older) Form W-4 for Montana withholding. A newly hired employee should also use the 2017 federal Form W-4 to calculate the number of allowances for Montana. The IRS recently released a new federal Form W-4, Employee’s Withholding Allowance Certificate, for 2018 to reflect the recent federal tax reform provisions. As a result, employees may revise the...