+amdg+
I have had great success not having to give anyone my SS#, especially medical facilities, laboratories.
You can always try to invoke the Privacy Act of 1974, and the fact that Identity Theft is rampant.
Insurance information should be sufficient enough to process your paperwork, especially since the SS# is technically only intended to be given to someone who has to report wages you earn to the IRS.
I have also told them that the SS Office has clearly explained that the number should be protected at all costs and should only be given to employers, then ask them the question "Were they wrong when they told me that?"
Sometimes when you ask them politely to clarify why they need your social, they drop the topic.
They have just gotten used to everyone answering their questions that you may end up throwing them off their game.
My impression of the situation is that if they have any billing issues, they try to threaten credit reporting, which they will need your SS# to do. Another good reason not to disclose it. As I have found out there is much fraud in medical billing, that when challenged, usually makes them go away. In fact, one fraudulent medical bill I received had the address of an Irish Pub in the neighboring town as the official address to send payments. The bill explained in bold writing not to send to the hospital but to their "office", which, when mapped on google, revealed an Irish Pub. There is so much fraud out there, everyone should be diligent about whom and when they are giving out their private information. Don't think anything of it, be determined not to allow yourself to be placed in a situation where you feel coerced to disclose such data.
You can always claim that you wish to avoid any identity theft issues, and cordially explain that they do not need your social to attend to your medical needs.
They may be insistent, but for the most part, they accept my decision to keep that data private.
Perhaps, you have not memorized it, and can provide it on your next visit, as you do not make a habit of carrying your social security card, for safety reasons.
Good luck, I hope it works out for you.
Peace and blessings, Francesca