More than 4.6 million U.S. citizen children live with at least one parent who lacks permanent legal status and faces potential deportation.
These children—defined as "at-risk" because their parents could be detained or deported—represent a vulnerable population whose futures depend directly on immigration enforcement decisions that could separate them from their parents overnight. The estimates come from independent research by the Brookings Institution and the Center for Migration Studies, both using demographic analysis of Census data and detention records. The true figure is difficult to pin down because the American Community Survey, the primary source for Census data, does not record immigration status, but multiple methodologies converge on similar numbers.
Table of Contents
- How Researchers Calculated the 4.6 Million Figure
- Who These Children Are
- The Immediate Cost of Parental Detention
- What a Mass Deportation Would Mean
- Why These Numbers May Not Tell the Whole Story
How Researchers Calculated the 4.6 Million Figure
The Brookings Institution estimated 4.6 million U.S. citizen children live with at least one parent lacking permanent legal status in May 2026. The Center for Migration Studies reported 4.71 million U.S. citizen children (6.7% of all citizen children) with at least one undocumented parent in May 2025. An earlier Migration Policy Institute study using 2009–13 Census data found 5.1 million children under 18 with at least one unauthorized immigrant parent, of whom 79%—or 4.1 million—were U.S. citizens.
"At-risk" does not mean these children are currently in danger; it means they are vulnerable to immediate separation if their parent is detained or deported. The Brookings figure assumes no mass deportation has occurred; it models baseline vulnerability to current enforcement.
Who These Children Are
Most are young. Of the U.S. citizen children who experienced parental detention between January 2025 and April 2026, 36% were under age 6, and 53.7% had parents from Mexico. This age distribution means many cannot understand or process what is happening to their family; the youngest may have no memory of their parent if separation occurs.
These children live with parents who lack permanent legal status. Their citizenship does not protect their family from the enforcement actions that already detained 145,000 similar children in the past year and a half.
The Immediate Cost of Parental Detention
Between January 2025 and April 2026, Brookings found that approximately 145,000 U.S. citizen children experienced the detention of at least one parent; about 22,000 lost both parents in the same household. These children entered foster care, were placed with relatives, or faced sudden economic collapse when their parent's income disappeared. The actual number of detained parents is harder to pin down. The Department of Homeland Security reported only 18,277 detained parents of U.S. citizens in fiscal year 2025, but Brookings identified this as "almost certainly a substantial undercount" because detainees are often not asked about children and do not disclose them out of fear.
What a Mass Deportation Would Mean
If the U.S. implemented a mass-deportation program, the impact would be severe. The Center for Migration Studies estimated that 2.66 million U.S. citizen children—3.8% of all citizen children—would have no parent remaining in the household. Another 66,000 children could be forced into foster care, costing U.S. taxpayers over $400 million annually in child welfare services alone.
These are not speculative numbers. They are projections built from documented detention rates and family household data. They assume no policy changes that would allow children to remain with parents or speed legal processing.
Why These Numbers May Not Tell the Whole Story
All current estimates rely on demographic modeling rather than direct counts, because immigration status is not recorded in the American Community Survey. The true figure depends on the year of data used, the methodology applied, and how "at-risk" is defined—whether it means exposure to detention, eligibility for deportation, or actual family separation. A reader should know that these estimates offer the best picture available, but they are not final.
As immigration enforcement changes, so does the actual number of children at risk. The data lags behind policy, and published estimates may be months or years old by the time they reach readers.