The Federal Data Services Hub: The Eligibility Engine Powering Medicaid & Health Insurance Marketplaces

Summary

The U.S. Citizenship and Immigration Services (USCIS) recently announced that the Systematic Alien Verification for Entitlements (SAVE) system can now provide a single source for verifying U.S. citizenship status nationwide. The agency claims that state and local authorities can input social security numbers — rather than immigration identification numbers — to verify U.S. citizenship and prevent ineligible immigrants from voting in U.S. elections. However, USCIS faces concerns that the agency made this change too quickly; the system depends on stale or unreliable data and questions about why USCIS did not rely on existing information architecture.

The federal government already has a history of using electronic data matches to verify U.S. citizenship status. The Federal Data Services Hub (FDSH) is a central federal system used to verify U.S. citizenship and immigration status and determine eligibility for Medicaid and health insurance marketplace coverage. It consolidates access to multiple federal databases (SSA, DHS, IRS, VA, and others). And it supports Medicaid and health insurance marketplaces by providing real-time verification of key eligibility criteria, including U.S. citizenship. The Government Accountability Office investigated states’ use of FDSH in September 2017 and found no indication that federal databases returned a false positive for U.S. citizenship. FDSH has become a trusted source for confirming U.S. citizenship for more than a decade.

Background

On May 22, 2025, U.S. Citizenship and Immigration Services (USCIS) announced that it had updated the Systematic Alien Verification for Entitlements (SAVE) system to provide a single source for verifying U.S. citizenship status nationwide. The agency claims that state and local authorities can now input social security numbers — rather than immigration identification numbers like an “A number,” or a naturalization number — to verify U.S. citizenship and prevent ineligible immigrants from voting in U.S. elections. While there are concerns that USCIS made this change too quickly and some uncertainty about the currency and reliability of the data, the concept of streamlined eligibility verification to ensure program integrity is not a new one for the federal government.

The Deficit Reduction Act of 2005 required U.S. citizen Medicaid applicants to provide documentation of their prince citizenship. This additional paperwork created a barrier for low income people trying to enroll in the program. Consumer advocacy organizations — including the Center on Budget and Policy Priorities,¹ and the National Health Law Program² — encouraged the use of electronic data matches and searches of state and federal records to prove U.S. citizenship rather than requiring applicants to obtain and submit documentation. Their hopes were realized in just a few years.

Medicaid agencies began conducting data matches to verify U.S. citizenship in 2007. Medicaid now has more than 15 years of electronic U.S. citizenship verification under its belt, and can provide a helpful learning tool on ways to reduce administrative burdens compared to requiring people to provide documentation of U.S. citizenship. And in 2014, both the federal and state-based health insurance marketplaces used the Federal Data and the Federal Data Services Hub (FDSH), which has been verifying citizenship for more than a decade.³ USCIS can learn from both Medicaid and FDSH.

A Brief History of U.S. Citizenship Verification in Medicaid

The Deficit Reduction Act of 2005 required Medicaid applicants to provide documentation of U.S. citizenship when they applied for or sought to renew Medicaid coverage. In the eight months following implementation of the requirement, states reported declines in Medicaid enrollment, particularly among low-income children, and increased administrative costs.⁴ However, in 2007, regulations allowed states to conduct electronic cross-matches with databases such as vital records, SAVE, and state motor vehicles departments if they confirmed U.S. citizenship and had evidence that the license holder was a U.S. citizen.⁵

Four years later, the Children’s Health Insurance Reauthorization Act of 2009 provided states the option of meeting this requirement by conducting a data match with the Social Security Administration to verify an applicant’s U.S. citizenship. In the first three months that the option became available, almost half the states adopted it, and SSA reported U.S. citizenship matches to be 94 percent successful overall. In other words, the matches confirmed U.S. citizenship for 94 percent of the people whose names states submitted to SSA. States reported that this process both eased procedural barriers to enrollment and produced administrative savings.⁶

The Creation of FDSH: How Verification of U.S. Citizenship in Medicaid and Health Insurance Marketplaces Works Today

The Affordable Care Act of 2010 (ACA), required all states to use an electronic data driven eligibility system for the majority of Medicaid and Marketplace applicants.⁷ The Federal Data Services Hub (FDSH) was then built to allow state Medicaid agencies and state-based health insurance exchanges to easily access multiple federal sources relevant for determining eligibility for Medicaid and qualified health plans in the health insurance marketplace. Most of the data sources were previously available to states, but had required multiple individual connections and data sharing agreements. FDSH included multiple databases housed within the Social Security Administration, the Department of Homeland Security, the Department of Veterans Affairs, the Internal Revenue Service and other sources including The Work Number (also known as TALX, a commercial data source from Equifax).⁸

FDSH provides 3 ways that states can verify U.S. Citizenship status for Medicaid:⁹

1. Social Security Administration: State Verification and Exchange System (SVES)/State Online Query (SOLQ): SOLQ is the online version of SVES that verifies U.S. citizenship in real time. Verifies U.S. citizenship for applicants born in the U.S. based on SSA records.
2. Department of Homeland Security Systematic Alien Verification (SAVE): An online service for registered federal, state, territorial, tribal, and local government agencies to verify immigration status and naturalized/acquired U.S. citizenship of applicants seeking benefits or licenses. It does not determine an applicant’s eligibility for a specific benefit or license. The benefit-granting or licensing agency determines eligibility for each benefit they administer.
3. State Vital Records Systems: 42 U.S. states plus DC, the U.S. Virgin Islands and Puerto Rico, participate in the Electronic Verification of Vital Events (EVVE) Program for electronic verification of vital events like births.¹⁰ These systems can verify U.S. birth certificates and other vital life records like deaths.

From the passage of the ACA until today, states have continued to rely on electronic verification of immigration and U.S. citizenship status for the majority of their Medicaid applications. The vast majority of SAVE and FDSH inquiries — which include verification of immigration status or U.S. citizenship status — have not required additional verification and the majority of total applications are processed within a few seconds or a day.

• The Government Accountability Office found that in 2012-2016, about 15.6% to 18.7% of immigration or U.S. citizenship queries needed additional verification.¹¹
• The Centers for Medicare and Medicaid Services shared that New York processed 80% of Medicaid applications in one sitting, and in Washington, 80% of applications were processed in under 24 hours in 2015.¹²
• The Urban Institute found that Colorado determined eligibility in real-time — within a few seconds of submitting their applications — for about 80% of Medicaid applicants for those who apply through the online application portal in 2017.¹³

FDSH has become a trusted source for confirming U.S. citizenship. The GAO investigated states’ use of FDSH to verify eligibility for state health insurance marketplaces in September 2017 and found no indication that federal databases returned a false positive for U.S. citizenship.¹⁴ In other words, the GAO did not find an indication that a federal database would return a “yes” for U.S. citizenship if an individual was not in fact a U.S. citizen. However, GAO did indicate that there could be false negatives (for example, SSA is unable to verify the U.S. citizenship of some U.S. citizens born abroad or people who change their names). These false negatives are typically handled through a “cure” process, allowing individuals additional opportunities and methods to establish the relevant requirements.

<sup>1. Leighton Ku et al, Documenting Citizenship and Identity Using Data Matches, Center on Budget and Policy Priorities, September 2006, https://www.cbpp.org/research/documenting-citizenship-and-identity-using-data-matches.
2. Manjusha P. Kulkarni, Fact Sheet: Citizenship Documentation Requirements Under the Deficit Reduction Act and Interim Final Rule, National Health Law Program, September 2006, https://healthlaw.org/resource/fact-sheet-citizenship-documentation-requirements-under-the-deficit-reduction-act/.
3. While the launch of the federally facilitated marketplace’s online enrollment system in 2014 was problematic, recent feedback from people signing up for coverage focused on plan choice and navigating coverage transitions. Verification of U.S. citizenship was not named as a problem. Kaye Pestaina et al, Signing Up for Marketplace Coverage Remains a Challenge for Many Consumers, KFF, October 30, 2023, https://www.kff.org/policy-watch/signing-up-for-marketplace-coverage-remains-a-challenge-for-many-consumers/.
4. Donna Cohen Ross, New Medicaid Citizenship Documentation Requirement is Taking a Toll: States Report Enrollment Is Down and Administrative Costs Are UP, Center on Budget and Policy Priorities, March 13, 2007, https://www.cbpp.org/research/new-medicaid-citizenship-documentation-requirement-is-taking-a-toll-states-report.
5. Medicaid Program; Citizenship Documentation Requirements, 72 Fed. Reg, 38662 July 13, 2007, https://www.federalregister.gov/d/07-3291.
6. Donna Cohen Ross, New Citizenship Documentation Option for Medicaid and CHIP is Up and Running, Center on Budget and Policy Priorities, April 20, 2010. https://www.cbpp.org/research/new-citizenship-documentation-option-for-medicaid-and-chip-is-up-and-running.
7. States determine financial eligibility automatically for about ¾ of Medicaid recipients based on Modified Adjusted Growth Income (MAGI) methodology. Alice Burns, et al, Medicaid Eligibility and Enrollment Policies for Seniors and People with Disabilities (Non-MAGI) During the Unwinding, KFF, June 20, 2024, https://www.kff.org/medicaid/issue-brief/medicaid-eligibility-and-enrollment-policies-for-seniors-and-people-with-disabilities-non-magi-during-the-unwinding/.
8. How to Streamline Verification for Medicaid and SNAP, Center on Budget and Policy Priorities, July 18, 2024, https://www.cbpp.org/research/health/how-to-streamline-verification-of-eligibility-for-medicaid-and-snap.
9. How to Streamline Verification for Medicaid and SNAP, Center on Budget and Policy Priorities, July 18, 2024, https://www.cbpp.org/research/health/how-to-streamline-verification-of-eligibility-for-medicaid-and-snap.
10. Myrna, Traylor, Validating Vitals: Electronic Verification of Vital Records Streamlines Identity Verification Process, American Association of Motor Vehicle Administrators, March 2020, https://movemag.org/validating-vitals/.
11. GAO, Immigration Status Verification for Benefits, March 2017, https://www.gao.gov/assets/gao-17-204.pdf Keep in mind that this could be a response related to verifying immigration status OR naturalized U.S. citizenship. It is not focused solely on U.S. citizenship.
12. CMS, Achieving Real Time Eligibility Determinations, CMS All-State SOTA Call, June 25, 2015, https://www.medicaid.gov/state-resource-center/mac-learning-collaboratives/downloads/real-time-eligibility-determinations.pdf.
13. ane Wishner, et al, Medicaid Real-Time Eligibility Determinations and Automated Renewals: Lessons for Medi-Cal from Colorado and Washington, Urban Institute, August 2018, https://www.urban.org/sites/default/files/publication/98904/medicaid_real-time_eligibility_determinations_and_automated_renewals.pdf.
14. GAO, State Health-Insurance Marketplaces: Three States Used Varied Data Sources for Eligibility and Had Few Indications of Potentially Improper Enrollments, September 2017, https://www.gao.gov/assets/gao-17-694.pdf.</sup>