The phone number for the direct line to social security is 410-965-0160 it is a direct line so you are not put on hold if no one answers you get a recording call back. You have to be persistent it took me over an hour of calling again and again until somebody picked up the phone. The agent told me it can take a few months for the letter to get there and then it take time again for them to scan it into the system. So if you call like I did and let them know you are alive and you tried mailing your form they may not cut your benefits if the letter arrives late the agent told me