The number of work credits you need to qualify for disability benefits depends on the age when you became disabled. You typically need 40 credits, 20 of which were earned in the last 10 years ending with the year you became disabled. Based on this method younger workers may qualify with fewer credits.
There are two highly published Tests that are outlined directly by the SSA:
Recent Work Test
The recent work test is based on the age you were when your disability began. The rules are based on calendar quarters. The first quarter runs January 1 through March 31; the second quarter runs April 1 through June 30; the third quarter runs July 1 through September 30; and the fourth quarter runs from October 1 through December 31.
If you become disabled in or before the quarter you turn 24, you generally need 1.5 years of work during the three-year period ending with the quarter your disability began.
If you become disabled in the quarter after you turn 24 but before the quarter you turn 31, you most likely need to have worked during half the time for the period beginning with the quarter after you turned 21 and ending with the quarter you became disabled.
If you become disabled in the quarter you turn age 31 or older, you need to work during five years out of the 10-year period ending with the quarter your disability began.
Duration of Work Test
This test determines how long you worked by the age you were when disability began. For example, if you become disabled before age 28, you need to have worked for 1.5 years. If you became disabled at age 42, you need 5 years of work. Disabled at age 60? You need 9.5 years of work. In any of these cases, for the duration of work test, your work does not have to fall within a certain period of time.