Check out this post - www.johnrdundon.com/the-new-draft-version-2019-form-w-4-is-a-rage-inducing-abomination/ - no the IRS does not 'require' that you prepare a new W4 form for your employer. Many employers however are 'requiring' employees to prepare, sign and submit new W4 forms. Either way it is a good idea to look closely at your income tax withholding, and now is a good time to do just that. The withholding calculator I believe has a high degree of likelihood of guiding you towards under withholding which can be problematic come next April. Best to consult your tax adviser.