A "Social Security credit" (sometimes referred to as a "Quarter of coverage") is the measure of a person's work under the Social Security program.
We use a person's total covered yearly earnings to figure Social Security credits for both wages and net earnings from self-employment. The amount needed for a credit increases automatically each year that average wages increase. For 2008, workers generally receive one credit for each $1,050 of earnings. For 2007, the amount of earnings for one credit was $1000. A worker can receive a maximum of four credits for any year.
Before Social Security credits can be earned for any year, a self-employed person usually has to have net earnings of at least $400. However, a person with actual net earnings from self-employment of less than $400 may still receive credits for years in which he or she uses the "optional method" of reporting earnings.
For the amount required for Social Security credits for prior years, see Quarter of Coverage.