Social Security Death Index

The Social Security Death Index (SSDI) is a database of death records created from the United States Social Security Administration's Death Master File Extract. Most persons who have died since 1936 who had a Social Security Number (SSN) and whose death has been reported to the Social Security Administration are listed in the SSDI. For most years since 1973, the SSDI includes 93 percent to 96 percent of deaths of individuals aged 65 or older. It is frequently updated; the version of June 22, 2011 contained 89,835,920 records.

Unlike the Death Master File, the SSDI is available free from several genealogy websites. The SSDI is a popular tool for genealogists and biographers because it contains valuable genealogical data. It is also useful for medical research such as clinical trials and epidemiology, because where survival data is missing from medical records (for reasons such as loss to follow-up), the SSDI can be used to backfill it.

The data include:

Once a deceased person is found in the database, the person's application for Social Security card (Form SS-5) can be ordered from the Social Security Administration. The SS-5 may contain additional genealogical data, such as birthplace, father's name, and mother's full maiden name or that information may be blacked out.

Given the growing problem of identity theft and the importance of the Social Security number as a personal identifier in the United States, it might seem unusual that these identifiers are released publicly. However, because the documents held by the Social Security Administration are government records, it is required to make the information public under the Freedom of Information Act (FOIA). In fact, the related Death Master File is used to prevent fraud so that no one can steal the identity of a dead person, and take out a credit card or a bank loan in a dead person's name.

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