Very sorry for your loss. For the year that your spouse passed away, you could file a joint return. IF you still have qualified dependent children, you can file as a Qualified Surviving Spouse for the next two years and get the same standard deduction that you would get on a married joint return. If you do not have dependent children, you will file as Single.
A W-4 indicates to your employer how much tax to withhold from your paychecks; it does not dictate how you file your tax return. A W-4 does not go to the IRS. It only goes to your employer.
If you do not have dependent children and will be filing as Single, you will need to start a new online account with a different user ID, because it is too difficult to use an account that was used for joint returns if you are changing your filling status to Single. Keep a record of how to access the old account that was used for joint returns in case you need to look at them again someday. TurboTax and the IRS save returns for seven years.
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...
https://accountants.intuit.com/support/en-us/help-article/tax-filing-status/claiming-qualified-survi...
https://blog.turbotax.intuit.com/tax-planning-2/tax-implications-for-taxpayers-who-have-lost-a-spous...
https://ttlc.intuit.com/questions/4149272-i-heard-that-the-federal-qualifying-widow-er-requirements-...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
