Social Security Income is counted on by 40% of Americans over age 65 to keep them above the poverty level, and millions of other elderly Americans to deliver an acceptable quality of life. For retirees, they become eligible for a reduced social security income at age 62. Full retirement benefits kick in depending on a retiree's year of birth. The income they receive is based on their Primary Insurance Amount (PIA), which is the average of the worker's highest 35 years of covered earnings. From this number, various formulas are used to determine the exact amount owed to individual retirees. Spouses, widows, dependents and the disabled all also are eligible to receive a social security income. Each of these cases must qualify for the benefits in accordance with a strict set of guidelines. These guidelines actually lead to the disability part of receiving a social security income to be the most legally contested, as more people are turned down for this program than any others, an the process for receiving the income can be quite complex.