Social Security provides monthly cash benefits to retired or disabled workers and their family members, and to the family members of deceased workers. Among the beneficiary population, almost 83% are retired or disabled workers; family members of retired, disabled, or deceased workers make up the remainder. In August 2017, nearly 62 million beneficiaries received a total of $77 billion in benefit payments for the month; the average monthly benefit was $1,258. Workers become eligible for Social Security benefits for themselves and their family members by working in Social Security-covered employment. An estimated 94% of workers in paid employment or self-employment are covered, and their earnings are subject to the Social Security payroll tax. Employers and employees each pay 6.2% of covered earnings, up to an annual limit on taxable earnings ($127,200 in 2017 and $128,700 in 2018). Among other requirements, a worker generally needs 40 earnings credits (10 years of covered employment) to be eligible for a Social Security retired-worker benefit. Fewer earnings credits are needed to qualify for a disabled-worker benefit; the number needed varies depending on the age of the worker when he or she became disabled. A worker's initial monthly benefit is based on his or her career-average earnings in covered employment. Social Security retired-worker benefits are first payable at the age of 62, subject to a permanent reduction for early retirement. Full (unreduced) retirement benefits are first payable at the full retirement age (FRA), which is increasing gradually from 65 to 67 under a law enacted by Congress in 1983. The FRA will reach 67 for persons born in 1960 or later (i.e., persons who become eligible for retirement benefits at the age of 62 in 2022 or later). In addition to payroll taxes, Social Security is financed by federal income taxes that some beneficiaries pay on a portion of their benefits and by interest income that is earned on the Treasury securities held by the Social Security trust funds. In 2016, the Social Security trust funds had receipts totaling $957 billion, expenditures totaling $922 billion, and accumulated assets (U.S. Treasury securities) totaling nearly $3 trillion. The Social Security Board of Trustees (the trustees) notes, "Over the program's 82-year history, it has collected roughly $19.9 trillion and paid out $17.1 trillion, leaving asset reserves of more than $2.8 trillion at the end of 2016 in its two trust funds." Projections by the trustees show that, based on the program's current financing and benefit structure, benefits scheduled under current law can be paid in full and on time until 2034 (under the intermediate set of assumptions). Projections also show that Social Security expenditures will exceed income by about 20% on average over the next 75 years. Restoring long-range trust fund solvency and other policy objectives (such as increasing benefits for certain beneficiaries) have made Social Security reform an issue of ongoing congressional interest. This report provides an overview of Social Security financing and benefits under current law. Specifically, the report covers the origins and a brief history of the program; Social Security financing and the status of the trust funds; how Social Security benefits are computed; the types of Social Security benefits available to workers and their family members; the basic eligibility requirements for each type of benefit; the scheduled increase in the Social Security retirement age; and the federal income taxation of Social Security benefits.