After you file

Only if you have not filed yet.  

To add a  W2 just type w2 (small W)  in the search box at the top of your return and click on Jump To the W2

 

OR  To Add a W2 enter it under

Federal Taxes on the left side

Wages & Income  

Then Wages and Salaries- Click the Start or Update button

 

Then if you are married you should have 2 buttons...Add w-2 for (taxpayer name) and Add w-2 for (spouse name). Click on the correct button to add a W-2.

 

BUT  if you already filed the first one.....

You cannot change or add anything on the return that you e-filed.  It is too late, just like when you put an envelope in a US mailbox

Now you have to wait until the IRS either rejects or accepts your return. If your return is rejected, you will be able to go into your account and add or change it and resend it.

If the IRS accepts your return, then you have to wait until it has been fully processed and you have received your refund or paid the tax due. THEN you can prepare an amended tax return 1040X and mail it in. You cannot e-file an amended return.  Meanwhile, DO NOT change anything on your return until you start the amended return. If you did change or add the missing info then take it out and put your return back to the way it was when you first filed it.

You can check your efiling status here,
https://turbotax.intuit.com/tax-tools/efile-status-lookup/

How to amend an Online return
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577