The specific requirements vary depending on the type of benefits, the age of the person filing the claim and, if you are claiming as a dependent or survivor, the age of the worker. There is one general requirement, however: The worker on whose earnings record the benefit is to be paid must have worked in "covered employment" for a sufficient number of years -- that is, earned enough of what Social Security calls work credits -- by the time he or she claims retirement benefits, becomes disabled, or dies. This usually means a total of at least ten years of work at which you or your employer paid into Social Security. To find out about your eligibility, call the Social Security Administration at 800-772-1213.

Note that Social Security has separate eligibility rules for some specific types of workers, including federal, state, and local government workers, workers for nonprofit organizations, members of the military, household workers, and farm workers. If you have been employed for some time as one of these types of workers, check with the Social Security Administration for the rules that may affect your eligibility.

Since its inception in 1936, Social Security considered 65 to be full or normal retirement age for the retirement benefit. Benefits amounts were calculated on the assumption that most workers will stop working full time and will claim retirement benefits when they reach age 65. While the system has long provided for early retirement, to give incentive for people to delay making their retirement claims, Social Security offers higher benefits for people who wait to make their claims after reaching full retirement age.

Now that people are generally living longer, however, the Social Security rules for what is considered full retirement age are changing. Age 65 is still considered full retirement age for anyone born before 1938. However, full retirement age gradually increases from age 65 to 67 for people born in 1938 or later.

Social Security most commonly refers to four programs financed through Social Security (FICA) payroll taxes: retirement pensions (frequently called old-age insurance), survivors insurance, disability insurance, and Medicare for the aged and disabled.

No. You may qualify for more than one type of Social Security benefit, but you can collect just one. For example, you might be eligible for both retirement and disability, or you might be entitled to benefits based on your own retirement as well as on that of your retired spouse. You can collect whichever one of these benefits is higher, but not both.

Since its inception, taxes from current workers have exceeded the benefits paid out to retired and disabled workers, as well as their survivors and eligible dependents. However, by 2013, benefits paid out are projected to begin exceeding Social Security tax income, with the balance made up from the federal government's general budget (as it begins paying back money borrowed from the Social Security trust fund during the many years that it ran a surplus). By 2032, the trust fund surplus is expected to be exhausted as the deficit between taxes paid and benefit costs reaches its peak.

Although the U.S. has continued to steadily grow since the baby boom generation, three factors have combined to create Social Security's future dilemma. First, the cost of Social Security benefits has continued to rise due to cost-of-living adjustments, the skyrocketing costs of medical care and the fact that Americans are living longer. Second, as the baby boomers entered the work force in the 1970s they had fewer babies (future workers) in what some called the "baby bust."

The third factor involves the changing source of growth, as high immigration replaced native-born births as the driving force behind U.S. population growth. In general, new immigrants have less education, lower skills, a higher tendency to avoid taxes, and overall lower earnings with consequently lower Social Security tax contributions
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