Yes, you need all of your W-2's to enter on your tax return, and they all must go on the SAME tax return.  Employers have until the end of January to issue your W-2.

Every W-2 that you received must be reported on your tax return, even if they are for small amounts.  Remember that each one of those W-2’s has your Social Security number on it, and that income was reported to the IRS by the employer.  You do not want to get in trouble with the IRS for under-reporting your income.

ALL of your W-2’s must be entered on the SAME tax return.  After you enter the first one, you click Add Another W-2.

You cannot file your 2017 tax return yet.  It is too early. Trying to file early and then ending up having to amend because you used incorrect/incomplete information is counter-productive.  If your return is incorrect, and you have to amend it, it will take months for the IRS to process your amended return.

Employers, banks, Social Security, brokers, etc. have until the end of January/early February 2018 to provide you with the documents you will need to enter on your 2017 tax return.

The IRS will not be accepting returns until an as yet undetermined date in January.  They will not begin issuing refunds until at least mid-February.

https://www.irs.gov/newsroom/irs-statement-on-2018-filing-season-start-date

https://www.irs.gov/newsroom/get-ready-for-taxes-plan-ahead-for-2018-filing-season-to-avoid-refund-d...

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