Do undocumented immigrants use Individual Taxpayer Identification Numbers to pay Social Security and Medicare taxes?
Executive summary
Yes—many undocumented immigrants use Individual Taxpayer Identification Numbers (ITINs) to file tax returns and, in doing so, pay federal payroll taxes that fund Social Security and Medicare, even though ITINs do not grant work authorization or eligibility for those benefits [1] [2] [3]. Independent analyses estimate billions flow into Social Security and Medicare from taxpayers filing with ITINs or otherwise undocumented workers, while the IRS and law limit ITINs to tax-processing purposes and prohibit their use to claim Social Security or Medicare benefits [4] [5] [6].
1. What an ITIN is and why undocumented people use it
An ITIN is a tax-processing number the IRS issues to people who are not eligible for a Social Security number so they can file federal tax returns; it was created to enable tax compliance, not to confer immigration status or work authorization [3] [6]. The IRS allows ITINs so residents who lack SSNs can report income and pay federal, state and local taxes; the Tax Policy Center and advocacy groups note that most ITIN filings come from people without SSNs—many of whom are undocumented—seeking to comply with tax law or document earnings for potential future immigration claims [1] [3] [7].
2. How payroll taxes get paid when someone files with an ITIN
Federal payroll taxes for Social Security and Medicare are typically collected through employer withholding on W‑2 wages or via self‑employment tax filed on Schedule SE; individuals without SSNs who file returns with ITINs can and do report wage and self‑employment income and pay these payroll taxes through their tax filings [1] [8]. The IRS treats ITIN filers as taxpayers for withholding and self‑employment purposes, and several reports itemize sizable Social Security and Medicare contributions traceable to ITIN returns or estimates of undocumented-worker payroll-tax payments [3] [4] [1].
3. How much is at stake—estimates from multiple studies
Multiple analyses converge on the point that undocumented workers contribute billions: the Institute on Taxation and Economic Policy estimated tens of billions paid into Social Security, Medicare and unemployment insurance in 2022, and other organizations and academic work have produced similar multi‑billion dollar figures for payroll contributions by undocumented residents [4] [9] [1]. The IRS and Taxpayer Advocate Service data show millions of ITIN returns and billions in reported taxable income and payroll‑related taxes on those returns, reinforcing that the tax contributions are substantial [1] [3].
4. Why these payments don’t lead to benefits for most ITIN holders
Holding an ITIN does not make someone eligible for Social Security retirement or Medicare benefits; eligibility generally requires an SSN and lawful work authorization or covered earnings credited to an SSN-based earnings record, so most contributions by undocumented workers are not matched to benefit entitlements unless the person later obtains lawful status and an SSN that can be linked to prior earnings [5] [6] [10]. Some undocumented workers nevertheless end up paying into Social Security using borrowed or false SSNs—payments that technically boost the Social Security Trust Fund but do not translate into benefits for the person whose identity was misused [11] [8].
5. Conflicting practices and reporting limits—what the sources don’t resolve
Reports differ in methodology—some measure taxes paid by ITIN filers directly, others estimate undocumented-worker payroll contributions using broader labor and tax models—so precise attribution of Social Security and Medicare dollars to ITIN filers versus workers using other means (e.g., false SSNs, employer reporting) is imprecise in public data [4] [1] [8]. The IRS’s confidentiality rules limit cross‑agency sharing of ITIN application data with immigration authorities, but they also mean researchers must infer undocumented contributions indirectly, creating unavoidable uncertainty in exact dollar figures and the breakdown by filing mechanism [6] [3].
6. Bottom line and policy tensions
The factual record across the IRS, policy analysts and advocacy groups is clear: undocumented immigrants frequently use ITINs to file taxes and, through those filings or other reporting mechanisms, contribute materially to Social Security and Medicare payroll tax receipts—yet ITIN status does not entitle them to claim those programs, and measurement challenges leave some details open to debate [3] [4] [5]. That dissonance—paying into programs without routine access to their benefits—drives ongoing policy, legal, and political discussions about immigration, labor markets, and program sustainability, with credible alternative viewpoints grounded in differing legal interpretations and data methodologies [5] [1].