Social Security disability is an insurance policy, and you gain that insurance coverage through the Social Security taxes that you pay when working. Social Security counts each quarter that you work as 1 credit.
How long do you have to work before you are initially covered for Social Security disability? It depends upon your age.
Before age 24, you need just 6 credits earned in the 3-year period prior to the onset of your disability.
Between age 24 and 31, you need to have credit for working half the time between age 21 and the onset of disability. For example, if you become disabled at age 27, you would need credit for 3 years of work (12 credits) out of the past 6 years (between ages 21 and 27).
Age 31 and older, you need to have earned 20 credits within the 10 years prior to the onset of disability. Further, you must have the total number of credits shown in this table.