A "work credit" is an accounting unit used by Social Security to determine eligibility for purposes of Social Security Disability Insurance (SSDI.)

• You earn 1 credit for each calendar quarter in which you earn a required minimum amount of money. AND pay Social Security tax on those earnings.
• If you work an entire year, you earn 4 credits. 
• The amount of earnings required for a credit is subject to change each year: in 2020 the requirement is $1,410 per quarter or $5,640 per year.
• NOTE:  You do not actually have to work the entire year to earn 4 credits. As soon as you earn 4 times the amount of the minimum quarterly wage, you earn 4 credits. So, a person who wants to stop work and start collecting SSDI benefits, but who is short a few credits, can earn the required credits in one calendar period. For example, for 2020, if you earn $5,640 in a quarter of the year, you receive 4 credits ($1,410 x 4= $5,640).
• Maximum credits per year: You can only earn up to a maximum of four work credits per year regardless of the amount of your earnings.

Family members who qualify for benefits on your work record do not need work credits.

In order for earnings to qualify, earnings must have been reported to Social Security, and F.I.C.A. payroll taxes must have been paid on them.

Earnings may consist of any of the following:

• nonagricultural wages
• military wages
• railroad compensation
• agricultural wages and
• self-employment income

The amount of money required to earn one work credit varies from year to year. The following table lists the amount of money required to earn a work credit, starting with 1978.