I actually had a great experience signing up for MC. I'm waiting a bit for SS. They did not have current amounts for my last 3 years of contributions. I set up an appointment on the phone, verified what I needed to present, and visited their office 5 days later. I waited ~3 minutes, and the representative greeted me warmly, looked at my documentation, and said: well, that's taken care of. I'll send you a confirmation next week and you'll be signed up. Any questions?
Thank you very much. I could have hugged her.