My 68 year old brother has been mentally disabled since age 14. He lived in MA. with my parents until they passed and had MA Health and Medicare. He now lives with me in N.H. (no more MA health) but still has Medicare. Tried to sign him up for Medicaid but needs more identification then he has. He has never had a job so has never filed taxes, never owned property, never had a drivers license but did have a picture ID from 1995 but unfortunately no one ever noticed his last name on it was misspelled so the DMV would not except it and he does not have an original SS card only a novelty card and the SS number on his card does not match his Medicare number because he is on my dads SS. So I have a photo ID with the wrong spelling, A SS card that does not match Medicare number, original birth certificate and a life insurance policy that by the way will not cover a funeral service. No one will accept what I have. The SS office wont accept without original SS card and number and without that the DMV wont give a photo ID. Anyone have ideas of how to get this done.
Now in the form on box 7 it will show his name & address that SSA had as of Sept 2013. So keep that in mind when SSA on-line asks for his address. Box 8 will have the claim number, so if it somehow is tied to your dad's SS then it will have dad's number and a letter afterwards (usually an "A") so if you enter bro's SS & it doesn't work try dad's SS #.
Now you can go on-line to SSA to get this and believe me right now there are lots of people going on-line to get it as they can't find the copy mailed in January and taxes are due next week! keep in mind that SSA is pretty sticky to deal with in person - sounds like you have encountered all that. Whatever you do on-line you do it as your brother and all on his behalf.
About the ID, see if you can get some mail sent to bro at your address and things that look more "official" so you can bring these along to get an photo ID from DPS. Most places want a utility bill type of thing, so what to do? You could call the local cable company and ask about what plans they have and can they mail you some information. You do this as your brother so he is getting the mail from Time Warner
Cable whatever. Presto! brother now has a "presence" at your address.
Also you can get him a magazine subscription. ANother item to show his address
Perchance is there an ARC program in your area? If so they seem to have lots of volunteers & volunteer families to help those who now suddenly find themselves dealing with a disabled family member. their day programs are pretty terrific and they do get "paid" for their work so it will establish more paperwork for your bro.
Good luck, none of this is easy but it is wonderful you are there for him.