Credits or Quarters
Social Security Disability Insurance (SSDI) benefits are available to claimants who have earned enough credits or quarters to reach fully insured status and who are found to be medically disabled.
As you work, you pay taxes into the Social Security system. Look at your paystub and you will see the taxes. As you work and earn income, you are accumulating credits or quarters (same thing). You can earn up to 4 credits each year (hence the quarter). In 2014, if you earn approximately $1,200 in 3 months, then you earn a credit.
If you become disabled before age 24, then you need approximately 6 credits. If you become disabled between the ages of 24 and 30 you need one-half of the time between age 21 and when you become disabled. After age 31, you must earn 20 credits in a 40 quarter period to become fully insured (5 years of work in a 10 year period).
If you reach your fully insured status then stop working, you will begin to lose your insured status. After age 31, think of a rolling 10 year window. If you work for 5 years straight and earn enough to receive 4 credits each year, then you reached your insured status. Say, for example, you work another 2 years, then you must stop working due to a disability. When you stop working, the 10 year window rolls. You would lose your insured status in approximately 5 years after you stopped working.
Why is this important? Because if you do not have insured status you cannot receive SSDI benefits. Keep in mind, you do not have to file an application for SSDI prior to the end of your insured status (called Date Last Insured), but you must prove that you became disabled before your Date Last Insured (DLI).
If you have not reached your fully insured status or you became disabled after your DLI, then you can only seek Supplemental Security Income (SSI) benefits.