Here's some things you can do:

• Ask your employer when they mailed out their W-2s.
• Did your employer mail your W-2 to an old address? If so, ask them to re-send it to the new one.
• See if you can import your W-2.

If you haven't received your W-2 by February 14, it's time to take action:

1. Grab your last 2017 paystub and call the IRS at 1-800-829-1040.
2. The IRS will ask you for some info before following up with your employer.
3. After notifying the IRS, you can either continue waiting for your W-2, or paper-file your return using Form 4852 and your last paystub. Instructions

If nothing worked, you would enter information on a substitute W-2.  Here is a TurboTaxHelp article for your reference:

https://ttlc.intuit.com/community/accessing/help/how-do-i-file-a-substitute-w-2-using-form-4852/00/2...