<p>Undocumented children in the United States remain systematically excluded from comprehensive preventive health care, not due to lack of need, but as a consequence of deliberate policy design. Drawing on lived experience as an undocumented child and current practice as a family medicine physician in a rural federally qualified health center, this commentary examines how insurance exclusion structures a two-tiered childhood health system within the same communities—and often the same families. National evidence demonstrates that undocumented children experience higher rates of uninsurance, delayed care, reduced preventive service utilization, and increased reliance on emergency departments, despite sharing comparable developmental and chronic disease risks with their insured peers. The absence of routine primary care undermines life-course health, exacerbates inequities, and shifts costs toward crisis-driven systems. This essay argues that framing child health coverage as contingent on immigration status represents a failure of public health logic, economic efficiency, and ethical responsibility. Ensuring universal access to preventive care for all children, regardless of status, is not only a moral imperative but a necessary investment in population health and health system sustainability.</p>