During interview or oathing, I was told to contact to Social Security Office - does anyone why do we need to contact and if we have to how to contact them?
I got my citizenship in CA few years ago, and I was also requested to contact SSA office. It is only to let them know about your immigration status and update their system from GC to US Naturalized Citizen. I recall they took a photo copy of my naturalization certificate and updated their system. I actually visited SSA office to update their system.