Death Master File

The Death Master File is a computer database file made available by the United States Social Security Administration since 1980. It is known commercially as the Social Security Death Index (SSDI). The file contains information about persons who had Social Security numbers and whose deaths were reported to the Social Security Administration from 1962 to the present; or persons who died before 1962, but whose Social Security accounts were still active in 1962. As of 2009, the file contained information on over 83 million deaths. In 2011, some records were removed from the file .

The data include:

• Given name and surname; and since the 1990s, middle initial
• Full date of birth
• Month and year of death; or full date of death for accounts active in 2000 or later
• Social Security number
• State and year (or year range) in which the Social Security number was issued
• Last ZIP code of the person while alive
• ZIP code to which the lump sum death benefit was sent, if applicable

The Death Master File is a subset of the Social Security Administration's Numident database file, computerized in 1961, which contains information about all Social Security numbers issued since 1936. The Death Master File is considered a public document under the Freedom of Information Act, and monthly and weekly updates of the file are sold by the National Technical Information Service of the U.S. Department of Commerce. It is used by financial and credit firms and government agencies to match records and prevent identity fraud.

The Death Master File, in its SSDI form, is also used extensively by genealogists. Lorretto Dennis Szucs and Sandra Hargraves Luebking report in The Source: A Guidebook of American Genealogy (1997) that the total number of deaths in the United States from 1962 to September 1991 is estimated at 58.2 million. Of that number, 42.5 million (73 percent) are found in the Death Master File. Other research published by the Social Security Administration in 2002 suggests that for most years since 1973, 93 percent to 96 percent of deaths of individuals aged 65 or older were included in the DMF. Today the number of deaths, at any age, reported to the Death Master File is around 95 percent.