How do SSDI and SSI payments differ?

The following answer is from:

The two programs are financed differently. 

Employment taxes primarily finance Social Security retirement, survivors and disability insurance benefits.

Generally, we pay Social Security benefits to eligible workers and their families, based on the worker’s earnings. 

Meanwhile, general taxes fund the SSI program, which serves the needy. SSI eligibility depends largely on limited income and resources.

The following answer is Attorney Walter Hnot’s annotated response to the previous answer. 

SSI equates to $735 (2017) a month, while SSDI can be anywhere from 0-$2,663, but averages around $1,200.  SSI is dictated by a statute each year, while SSDI is an averaging algorithm of the past 35 years of what you have earned, and paid taxes on.

SSI Figures…


Unrounded annual amounts for—

Monthly amounts for 2017


2017 a

Eligible individual




Eligible couple




Essential person




The unrounded amounts for 2017 equal the unrounded amounts for 2016 increased by 0.3 percent.