Daniel Carson provided a good answer to your specific question, but it's possible you may not even need a W2 to complete your taxes.
In a comment from your thread from last year, Ben Miller asked if you received a paystub, and your response was:
No. It's just a check with an X amount payable to me. No pay stub or anything else.
The most important thing is to determine if you were paid as an employee or a contractor. Do you remember if you filled out a W4 (employee) or W9 (contractor) form?
Was the amount of the check equal to the amount you agreed to get paid according to the contract you signed?
- If yes, then it is very likely that you were paid as if you were an independent contractor, and if the total amount you were paid in 2016 was more than $600, you should be receiving a 1099 form in the mail, but even if you don't you can still file your taxes based on the exact total amount you were paid.
- If no, (your check was for less than the the contracted amount), then you were likely paid as an employee with taxes withheld. In this case you should receive a W2, and if you don't your former employer is obligated to provide you with one, and you can proceed as planned by contacting them, or the IRS if they need an extra nudge.
Update: In a comment below, Joe pointed out that if you file as if you received a 1099 you would also be paying the employer portion of FICA, and I agree with him that this may be unfair. Normally, if you can't decide if you are an employee or an independent contractor, there is a set of rules which help determine it, and the scale is heavily weighted towards being an employee. I have heard of many cases of the IRS reclassifying independent contractors as employees, but I have never heard of a single case of the reverse. Therefore, since you have a contract with your employer specifying that you would be an employee, IMHO that by itself should be proof enough that this was the intention under which your work was performed, and you should not be held liable for the employer portion of FICA. Unfortunately, in order to avoid paying it, you may have to fill out additional paperwork. Note the amount you will save will be 7.65% of the amount you were paid from that employer, (unless you made more than $118,500 in 2016, in which case it will be less), so that may help you determine if it's worth it.
If you decide to save the 7.65%, instead of filing as if you received a 1099, you can follow these instructions. In your case, the first bullet point applies to you:
You had a job and your employer ended up not paying you as an employee, but as a freelancer.
(You actually don't know with 100% certainty what your employer was thinking, but based on our conversation in the comments I think it's extremely likely that no taxes were withheld or paid.)
The summary of what the article describes is that you'll need to fill out Form 8919 and Form SS-8.