If I upgrade my comcast email to yahoo do I have to change my log ins on other websites that I sign in with my xfinity email with

@user_jfble0 

I am being prompted to update my email address to yahoo. I want to know if I do this upgrade will I have to go to every website/app that I log into and  change my log in to the new email address

For the moment, migrating to Yahoo! Mail is option, but that could change any time.

When you do migrate you'll login at either https://login.yahoo.com or https://mail.yahoo.com with your comcast.net credentials.  Your comcast.net email should not change from what it is now; only the server where you get your email changes.