Why I am getting a W-2c ? Should I call the IRS about this?

Have a W-2c on the way....Since I deferred some of my social security tax last year, I guess I will be getting a form from my employer once I repay what I deferred. Now how do I pay this? Where do I go? Do I have to wait until they send me this form first.Both of my taxes were accepted now I have to amend using the W-2c? I did to pay this ASAP so I won’t owe taxes or pay penalties???? Help