Can my dad change his social security deposit to a joint bank account with me?

I am on my father-in-laws bank account and his social security deposit goes into that account. He just had to be at the bank with me to give his permission for me to be on his account with him.

We already have a joint account, we just want to change it so my mother can't access his money

If you do, don't mix your money with his for that could create problems if he ever has to apply for Medicaid. Are you his durable P O A? If so, that gives you the authority to pay his bills from his account as his P O A.

I am assuming he has direct deposit to a checking account. If so, all he needs to do is add your name to the account.

Changing his direct deposit to another account means SS will have to be notified about the change. I would not close #1 account till ur sure #2 has direct deposit coming to it. Don't put any of your money into the accounts. If he ever needs Medicaid, any acct with his name on it will be considered his.

I was on my mother’s account and her check was deposited into it. I’m not sure if you’d have to open a new account or if the bank could just add you onto his. Best to call the bank.