SSD comes from FICA taxes that are deducted from paychecks during the work history of a person. Every month that a person works and reports income to the government, taxes are deducted which are paid into social security. When FICA taxes are taken out of paychecks, most of it goes into the social security retirement fund. However, a smaller portion goes into the social security disability fund. People who become disabled over their lifetime and are not yet eligible to get their full age retirement benefits can get benefits from the disability fund. One difference between SSD and SSI is that SSD is like social security retirement – it does not matter how much money a person has or how many assets they have.
SSI is a different program for disabled people and it is like a form of welfare. Like food stamps, if you have too much money, assets or property, then you will be ineligible for SSI even if you are clearly disabled. SSI is for people who are either too young to have paid enough into the system or have not worked recently enough to receive SSD. The benefits given to SSI claimants come from the general US government fund. To receive SSI, a claimant has to be equally disabled to a person who receives SSD – the standard for determining disability are the same. The only difference in deciding which claimant receives SSD or SSI comes from the amount of money paid into the social security system over one’s lifetime.