SNAP and WIC Administrative Data
This page provides the following information about how approved extramural researchers (with approved projects) can access SNAP and WIC administrative data acquired by the Census-FNS-ERS Joint Project.
The Census-FNS-ERS Joint Project is a strategic partnership between the USDA's Economic Research Service (ERS) and Food and Nutrition Service (FNS) and the U.S. Department of Commerce, Bureau of the Census. FNS is the agency responsible for administering USDA’s domestic food and nutrition assistance programs, such as the Supplemental Nutrition Assistance Program (SNAP) and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The Joint Project is a long-term cross-agency effort to acquire administrative data from States, for statistical and research purposes, on USDA food assistance programs. The project leverages those data through linkages to surveys conducted by the Census Bureau and to other administrative data files.
The project builds resources to conduct policy-relevant analysis, using administrative data and linking multiple data sources, gaining insights and results that are unobtainable using any data source alone. The research helps inform USDA, Congress, State agencies that administer food assistance programs, and the U.S. public on who participates in USDA food assistance programs, how program participation affects the lives of those individuals, and who does not participate and why. At the same time, the Joint Project informs decisions about how to improve Census Bureau surveys (which collect data on food assistance participation), the decennial Census of Population and Housing, the measurement of poverty, and data-linkage processes.
The Census Bureau conducts a variety of research projects that use administrative records linked to census and survey data. These projects are supported by the Data Linkage Infrastructure, in which the Census Bureau is: expediting the acquisition of Federal and federally-sponsored administrative data sources; improving data documentation and linkage techniques; and leveraging existing systems for governance, privacy protection, and secure access to these data. The Census Bureau has been leveraging external data sources since the 1940s; the Joint Project is not unique—it is another important example in a long history of Census Bureau work in this field.
The Joint Project is pioneering in its use of USDA administrative data acquired from State SNAP and WIC agencies. These partnerships have led to the development of the Next Generation Data Platform where USDA administrative data reside and link to other data sets.
The Next Generation Data Platform benefits ERS, the Census Bureau, FNS and the States, and supports guidance provided by the U.S. Office of Management and Budget in M-14-06 (Guidance for Providing and using Administrative Data for Statistical Purposes). The project partners within the Census Bureau are the Center for Economic Studies (CES) in the Research and Methodology Directorate and the Economic Reimbursable Surveys Division (ERD) in the Economic Directorate.
The goals of the Census-FNS-ERS Joint Project are to:
- Acquire, at the Census Bureau, the State-level administrative data of the Supplemental Nutrition Assistance Program (SNAP, formerly known as the Food Stamp Program) and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC);
- Leverage those data through linkage to other program and national survey data files;
- Collaborate on understanding data quality characteristics of administrative records; and
- Conduct joint research on issues that inform FNS and State SNAP and WIC agencies on administering USDA programs, and inform the Census Bureau on survey-improvement activities.
The Joint Project is a national undertaking. State SNAP and WIC agencies that participate send their confidential micro-data (involving millions of records that must be maintained in a secure data environment) to the Census Bureau in exchange for State-specific analyses and reports. ERS researchers (with Census Special Sworn Status) and Census Bureau staff use the States’ administrative data and linked data for joint research. Non-Federal researchers with Census Special Sworn Status can access the SNAP or WIC administrative data for approved projects through a Federal Statistical Research Data Center (FSRDC).
The two USDA programs in the Census-FNS-ERS Joint Project are SNAP and WIC. SNAP is USDA’s largest food assistance program—serving about 40 million people per month, about 12 percent of the Nation’s population—at a cost of approximately $79 billion in fiscal 2020. WIC provides nutrition assistance to some of the country’s most vulnerable populations, serving about 6 million people per month, at a cost of approximately $5 billion.
Understanding USDA food assistance programs and policies gains strength through access to confidential micro-level administrative data on participation, duration, and amount of benefit receipts. Administrative records are known for their completeness and accuracy. The records’ power as a research tool is multiplied when linked with either a survey or another administrative file, supporting research that could not be conducted using any one data source. The participation of FNS and ERS in the project is essential for conducting research that informs policy and operations decisions of USDA food assistance programs.
The availability of SNAP and WIC administrative records enhances Census Bureau operations and extends demographic and socioeconomic research capabilities through record linkage and statistical matching. Administrative records data can advance the mission of the Census Bureau by making operations more efficient, improving data quality, reducing data collection and processing costs, and reducing respondent burden. CES staff combine information from multiple sources to create new data products that could not be produced using single data sets.
The Joint Project addresses several barriers that historically have made it difficult to conduct research using administrative data from USDA food assistance programs. The project needed the cooperation of all three agencies to overcome these barriers: State-level USDA data, restrictions on allowable uses of administrative data, confidential data requirements, and statistical complexities.
State-level data: One barrier to the ability to research this information is that no national data exist for all program participants in either the SNAP or WIC programs. Data for SNAP and WIC are collected by States and reside at the State level. The Joint Project is undertaking a large-scale effort to contact all State SNAP and WIC agencies (which are different agencies at the State level) and to negotiate data-sharing agreements. The Census Bureau has the staff and expertise to make the contacts and develop the agreements. FNS involvement enhances the willingness of States to enter into data-sharing agreements for the project. In addition to the contributions of the Federal partners, the States’ SNAP and WIC agencies have State-specific expertise of their own Management Information Systems. Staff in the State agencies are instrumental in the process of extracting data and providing explanations to the Joint Project on the structure, format and meaning of the fields.
Data restrictions: Statutory and regulatory restrictions on the use of SNAP and WIC administrative data can present a second barrier. Specifically, the data can be used for research only if that research informs program administration. FNS approval of the Joint Project’s research enables the research to meet the statutory and regulatory requirements. FNS has programmatic expertise on the issues important to SNAP and WIC administration. Another statutory restriction is that accessing confidential Census Bureau data requires research to provide a benefit to the Census Bureau. A final restriction is that ERS researchers and non-Federal researchers must obtain Special Sworn Status as Census Bureau agents.
Data management: Once the Census Bureau receives a State’s data extract containing millions of confidential records, the data need to be cleaned and edited, reformatted, and linked in a secure data environment where access is restricted to approved researchers working on approved projects. Within the Census Bureau, the Center for Economic Studies and the Economic Reimbursable Surveys Division have the physical and intellectual capital for managing data to maximize use while maintaining data confidentiality and integrity.
Statistical complexities: ERS researchers contribute expertise in economics, other social sciences, and statistical disciplines. ERS links administrative and survey data sets to conduct research. ERS uses these links to overcome statistical complexities in using and merging large-scale data sets, such as modeling a USDA food assistance program and people’s behavioral responses to the program. ERS also provides financial support to facilitate data acquisition and management activities. ERS works in tandem with FNS and the Census Bureau to identify the policy and economic issues undertaken by the Joint Project.
Certain data collected in the Census-FNS-ERS Joint Project are available on a restricted-use basis to authorized Federal and non-Federal researchers (working on approved projects) through Federal Statistical Research Data Centers (FSRDC). At an FSRDC, researchers with Census Special Sworn Status, working on approved projects, have on-site (in-person) data access. Data may be used for statistical purposes only—not for regulatory or law enforcement purposes. Census Bureau staff reach out to State SNAP and WIC agencies to solicit their interest and participation. FNS encourages States to share USDA administrative data with the Census Bureau; some States also provide administrative data from the Temporary Assistance to Needy Families (TANF) program.
Researchers interested in submitting an application to access the restricted-use SNAP and WIC data (for States and years for which the data are available) are asked to contact the FSRDC, where they would conduct the research.
As of April 2022, the following State SNAP and WIC Agencies make restricted-use administrative data and lists of variables available for research through an FSRDC:
|State||(Calendar) Years for which data are available|
|California – Los Angeles County only||2017, 2018, 2019, 2020|
|Connecticut||2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015|
|Iowa||2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|Maryland||2017, 2018, 2019|
|Montana||2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|Nebraska||2018, 2019, 2020|
|Nevada||2017, 2018, 2019, 2020, 2021|
|North Carolina||2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|South Carolina||2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|South Dakota||2015, 2016, 2017, 2018, 2019, 2020|
|Wyoming||2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|Colorado||2017, 2018, 2019, 2020|
|Connecticut||2016, 2017, 2018, 2019, 2020, 2021|
|Illinois||2017, 2018, 2019, 2020|
|Kansas||2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021|
|Maine||2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020|
|Montana||2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020|
|South Dakota||2015, 2016, 2017, 2018, 2019, 2020|
For both SNAP and WIC data, different States send different sets of variables to the Census Bureau. State-by-State lists of variables, along with background information on administrative data, are available:
- Guide to variables for SNAP Administrative Data available through a Federal Statistical Research Data Center (FSRDC)
- Guide to variables for WIC Administrative Data available through a Federal Statistical Research Data Center (FSRDC)
Requesting Access to SNAP or WIC Administrative Data through an FSRDC
Researchers that would like to request access to the confidential SNAP or WIC data (for States and years for which the data are available; see above) must submit a project proposal, which is subject to approval, to the FSRDC where the researcher would conduct the research. To prepare a proposal, researchers should work directly with the FSRDC Administrator. The Administrator (a Census Bureau employee) will provide proposal development guidance to the researcher. The Census Bureau, which manages the FSRDC program, will route the proposal through review by the Census Bureau and FNS. Both parties must approve a proposal as a precondition to gaining data access. Additional reviews may be necessary depending on the data requested.
In addition to approval of a proposal, access to SNAP and WIC data (through an FSRDC) requires a researcher: (1) to obtain Census Bureau Special Sworn Status, and (2) to complete annual training for initiating and maintaining access to data collected under the Confidential Information Protection and Statistical Efficiency Act (CIPSEA). FSRDC Administrators can provide more information on either of those requirements.
The scale of the Joint Project is large, and its scope is broad. At its fruition, the Census-FNS-ERS Joint Project:
- Obtains, updates, and maintains large-scale administrative SNAP and WIC micro-data files obtained from States (including confidential data on millions of records that must be maintained in a secure data environment). The files contain critical information on the particulars of a State’s distinct legal, computer and technical-support infrastructure;
- Houses administrative data relevant for ERS research (and Census Bureau survey-improvement activities) that are obtained across the Federal government—including data supplied by the Departments of Labor, Treasury, Health and Human Services, Veterans Affairs, and the Social Security Administration;
- Provides ERS researchers with Special Sworn Status access to the Census Bureau’s premiere national surveys of households, including confidential data that are not publicly released;
- Leverages the information content of any one file by creating and updating linked databases, using state-of-the-art file-linking protocols and infrastructure provided by Census Bureau staff (for example, Census Bureau’s Person Identification Validation System (PVS) methodology);
- Enhances the effectiveness of using the Platform’s data for ERS research through:
- Improved frameworks and documentation for understanding the quality of raw administrative data, as received from data suppliers, and
- Refinement of the data-intake process—the procedures by which raw administrative data are cleaned, organized, and prepared for analysis files used by researchers;
- Provides access to data collected in the Census-FNS-ERS Joint Project; data access is provided to authorized Federal and non-Federal researchers working on approved projects through Federal Statistical Research Data Centers.