Tuesday, June 21, 2011

How Reliable is the SSDI?

How good is the information from the Social Security Death Index (SSDI)? It may not be as good as you think.

“The full DMF [Death Master File] includes both the verified and unverified reports of death for Social Security beneficiaries and non-beneficiaries,” said Bill Gray, an official of the Social Security Administration (SSA). The DMF is the government’s name for the Social Security Death Index. “We receive approximately 2.5 million death reports each year from many sources. We receive 90 percent of the reports from family members and funeral homes, with the remainder coming from States and other Federal agencies through data exchanges and reports from postal authorities and financial institutions.”1

According to Gray, over 90% of the information is unverified. Because studies showed that the Information obtained from family members and funeral homes is 99% accurate, SSA does not verify it. Information obtained about individuals who were not receiving Social Security benefits is also not verified, as the agency does not have the necessary contact information. Otherwise, deaths are verified through family members, payees, or medical institutions.

Gray said that states are allowed to prohibit redisclosure of death information they provide. The SSA removes such unverified state information to create the public version of the DMF. Genealogy websites rename and publish the DMF as the Social Security Death Index. Many supplement the DMF with additional information. Some websites add the state of issue, deriving it from the numbers in the SSN. Some provide city and state for zip codes. Users are advised to consider the city name with care, as the DMF is not updated as zip code boundaries change. Further, zip codes may cover multiple cities and genealogy websites may not display the correct one.

Gray considers the data to be 99.5% accurate. But as you evaluate the strength of the information, keep the following in mind.

  • The SSDI does not list the source of each entry nor does it indicate how the information was verified.
  • Most websites do not show the “Verify or Proof Code” from the DMF. This code indicates entries that have been verified and entries that have been proven by death certificate.
  • If the verified code is not displayed and the person died before retirement age, chances are he or she were not receiving benefits, and thus the information was not verified.

The SSDI does not contain information on every death. While coverage has increased dramatically since the early 1960s, coverage for the young remains low because they die before receiving benefits.2

SSDI coverage varies by age 
Estimated percentage of deaths included in the SSDI, by age, 1960-1997
Image credit: Hill and Rosenwaike

Next week: The SSDI on Ancestry.com and FamilySearch.org. 


     1.  Bill Gray, “Testimony before the Permanent Subcommittee on Investigations of the Senate Committee on Homeland Security,” 9 July 2008, Social Security Online (http://www.socialsecurity.gov : accessed 14 June 2011), legislation and congressional affairs.

     2.  Mark E. Hill and Ira Rosenwaike, “The Social Security Administration’s Death Master File: The Completeness of Death Reporting at Older Ages,” Social Security Bulletin 64, no. 1 (2001/2002): 48; PDF online (http://www.socialsecurity.gov/policy/docs/ssb/v64n1/v64n1p45.pdf : accessed 14 June 2011), “Research Statistics, and Policy Analysis” > “Research and Analysis.”

     3.  “Social Security Testimony Before Congress : Ways and Means Social Security Subcommittee,” 8 November 2001, Social Security Online (http://www.ssa.gov : accessed 14 June 2011), legislation and congressional affairs.


  1. Also it lists the "last residence"--not the place they died. My husband was his father's executor. His father's "last residence" is listed as Louisiana, because we lived there. His father never even visited Louisiana.

  2. My son died may 21, 2011 at age 49. SSDI shows Feb 21, 2011 verified with death certificate. He never received benefits.

  3. Have you seen this article Dick Eastman blogged about today? The SSDI adds about 14,000 people per year who are still alive!

  4. Those are the best footnotes I've ever seen on a genealogical blog (other than my own). Wow.


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