<prompt> Human: Hello,Like the title says, Im getting married later this year. Its my understanding that despite getting married at the end of the year, the IRS treats my filing status as married the entirety of 2017. So, do I just change my W-4 now? Is there any reason to wait until after Ive gotten married. November. I believe I just change it now, I just was hoping someone more knowledgeable would confirm.  <response>: You could change it now but beware that its more complicated than just checking married. Youll want to coordinate with your future spouse to work through the two-earners worksheet on the W-4 instructions. 