The Death Master File (DMF) is a computer database file made available by the United States

Social Security Administration The United States Social Security Administration (SSA) is an Independent agencies of the United States government, independent agency of the Federal government of the United States, U.S. federal government that administers Social Security (United ...

since 1980. It is known commercially as the Social Security Death Index (SSDI). The file contains information about persons who had

Social Security number In the United States, a Social Security number (SSN) is a nine-digit number issued to United States nationality law, U.S. citizens, Permanent residence (United States), permanent residents, and temporary (working) residents under section 205(c)(2 ...

s and whose deaths were reported to the

from 1962 to the present; or persons who died before 1962, but whose Social Security accounts were still active in 1962. , the file contained information on 111 million deaths. In 2011, some records were removed from the file.

Overview

The data includes: * Name (

given name A given name (also known as a forename or first name) is the part of a personal name quoted in that identifies a person, potentially with a middle name as well, and differentiates that person from the other members of a group (typically a f ...

surname In many societies, a surname, family name, or last name is the mostly hereditary portion of one's personal name that indicates one's family. It is typically combined with a given name to form the full name of a person, although several give ...

), since 1990s the middle initial * Date of birth (year, month, day) * Date of death (year, month), since 2000 the day of month *

* Whether death has been verified or a death certificate has been observed. In 2011, the following information was removed: * 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 In mathematics, a Set (mathematics), set ''A'' is a subset of a set ''B'' if all Element (mathematics), elements of ''A'' are also elements of ''B''; ''B'' is then a superset of ''A''. It is possible for ''A'' and ''B'' to be equal; if they a ...

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 The National Technical Information Service (NTIS) is an agency within the United States Department of Commerce, U.S. Department of Commerce. The primary mission of NTIS is to collect and organize scientific, technical, engineering, and busines ...

of the U.S.

Department of Commerce The United States Department of Commerce (DOC) is an United States federal executive departments, executive department of the Federal government of the United States, U.S. federal government. It is responsible for gathering data for business ...

. Knowing that a patient died is important in many observational clinical studies and is important for medical research. It is also 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

genealogist Genealogy () is the study of families, family history, and the tracing of their Lineage (anthropology), lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family ...

s. 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.

Distribution

distributes the file via

. In May 2013, the cost of a single download (with no weekly, monthly or quarterly annual subscription costs) was $1825.

Errors and omissions

The Social Security Administration has estimated that about 16 million decedents were missing from the file, leading to government benefits being paid out improperly; the total amount of improper payments in 2014 was estimated at $124 billion. Conversely, the Social Security Administration estimates that roughly 12,000 living people are added to the file annually, potentially due to clerical error. Because the file is used widely for commercial purposes, an erroneous listing can lead to not only a cessation of government benefits, but also the freezing of

bank account A bank account is a financial account maintained by a bank or other financial institution in which the financial transaction A financial transaction is an Contract, agreement, or communication, between a buyer and seller to exchange goods, ...

s, the inability to buy or rent property, and mistaken accusations of

identity theft Identity theft, identity piracy or identity infringement occurs when someone uses another's personal identifying information, like their name, identifying number, or credit card number, without their permission, to commit fraud or other crimes. ...

. The

Office of the Inspector General In the United States, Office of Inspector General (OIG) is a generic term for the oversight division of a List of federal agencies in the United States, federal or state agency aimed at preventing inefficient or unlawful operations within their p ...

called the error rate "very low", but noted that "SSA’s erroneous death entries can lead to mistaken benefit terminations and cause severe financial hardship and distress to affected people. ... When errors like this occur, it can be a long and difficult process to resurrect your financial life."

Use in immigration enforcement

In April 2025,

CBS News CBS News is the news division of the American television and radio broadcaster CBS. It is headquartered in New York City. CBS News television programs include ''CBS Evening News'', ''CBS Mornings'', news magazine programs ''CBS News Sunday Morn ...

, ''The New York Times'' and ''The Washington Post'' reported that over 6,000 living people were added to the Death Master File at the direction of the Trump administration. The additions to the Death Master File reportedly consist of immigrants that were granted

parole Parole, also known as provisional release, supervised release, or being on paper, is a form of early release of a prisoner, prison inmate where the prisoner agrees to abide by behavioral conditions, including checking-in with their designated ...

under policies initiated by the Biden administration.

References

External links