Social Security Administration: Observations on Use and Costs of Social Security Cards, Statement of Elizabeth H. Curda, Director, Education, Workforce, and Income Security, Testimony Before the Subcommittee on Social Security, Committee on Ways and Means, U.S. House of Representatives [open pdf - 221KB]
From the Highlights: "SSA [Social Security Administration] has issued about 500 million SSNs [ [Social Security numbers] and cards since the first design of the SSN and card in 1936. SSA provides a card to each individual when it issues an SSN, as required by law, and also issues replacement cards upon request. Concerns about costs and identity security in an increasingly paperless society have raised the question of whether a paper SSN card is still needed. GAO [Government Accountability Office] was asked to examine the use of the card. This testimony focuses on (1) federal requirements for individuals to present an SSN card; 2) stakeholder views on the purposes for which the cards are used; and (3) potential implications of eliminating SSN cards and developing alternative approaches."
Government Accountability Office: http://www.gao.gov/