SSDI is not welfare. It is not a benefit that is given out based on "need." If Brad Pitt or Julia Roberts became disabled, either one of them could collect SSDI . . . regardless of how many millions of dollars they had in the bank.

SSDI is simply when you take Social Security early because you can no longer work due to disability. SSI is welfare provided by the federal government. It is "means tested," meaning you have to be poor to get it.