The Social Security Death Index (SSDI) is generated from the U. S. Social Security Administration's Death Master File and it is used by the Social Security Administration for coordinating benefits. The Social Security Death Index is a perfect starting point for your family history research and a wonderful resource for genealogists because it contains information on millions of deceased individuals who had social security numbers and whose deaths were reported to the Social Security Administration. The SSDI includes entries from every state in the United States and covers deaths in the United States between 1800 and 2013.
The Social Security Administration does not guarantee the accuracy of the DMF file. Therefore, the absence of a particular person on the file is not proof that the individual is alive. If a person is missing from the index, it may be that the SS death was not reported to the Social Security Administration (SSA), the SS death benefit was never requested or the possibility that an error was made when entering the information into the SSDI.