I received my W2 and several weeks later my employer sent me a W-2c in the mail.
When I go into TurboTax, it downloaded my W2 from ADP Payroll.
Next, I edited the W2 info that was downloaded by adjusting the numbers to match what was on the W-2c. (the changes were only in regard to healthcare amounts).
Is that all I need to do and then efile and be done, or am I supposed to be mailing a paper copy of the W2 and/or W-2c to the IRS?
Did you already e-file your return before you received the corrected W-2C form?
If you didn't e-file your return before you received the W-2C, then you may simply log back in to your return and make the necessary changes, and then e-file.
You do not need to send the IRS a copy of your W-2C if you do not need to amend.
If you already mailed your return, or it was accepted (before you received the W-2C), you will need to amend it.
If you do need to amend your tax return, you should wait to file your amendment until you have received your refund or three weeks from the date of payment of taxes due.
Amend your return:
For more information, please read this TurboTax article: How to File an Amended Tax Return with the IRS