That's correct. The Social Security "trust fund" is really just an accounting fiction. Most of the money paid in SS taxes always went right back out to recipients. For awhile the government was collecting more than it was paying out (for demographic reasons) and the surplus was borrowed by the government. But I believe at this point the program has a negative cash flow, so the government will have to issue new bonds to pay off the bonds in the "trust fund".

It's really a lot like your right pocket borrowing from your left pocket.