First, if there's any way possible, you should try to recover your W-2 from your previous employer.
- 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 that doesn't work out, you may try the following:
- Grab your last 2016 paystub and call the IRS at 1-800-829-1040.
- The IRS will ask you for some info before following up with your employer.
As a last resort, you can file a conventional paper return that includes IRS Form 4852 if all efforts to obtain a W-2 from your employer have failed. Please see the TurboTax FAQ below for how to include this form.
https://ttlc.intuit.com/replies/5451995