Just a quick check of the official website to try and get onto Medicaid in WA state shows that it requires a social security number and citizenship information: https://www.wahealthplanfinder.org/us/en/health-coverage/get...
Just because it's illegal doesn't mean it isn't happening. From a May 25, 2025 article on the official CMS website: "The Centers for Medicare & Medicaid Services (CMS) announced today increased federal oversight to stop states from misusing federal Medicaid dollars to cover health care for individuals who are in the country illegally. Under federal law, federal Medicaid funding is generally only available for emergency medical services for noncitizens with unsatisfactory immigration status who would otherwise be Medicaid-eligible, but some states have pushed the boundaries, putting taxpayers on the hook for benefits that are not allowed."
From this article: https://www.cms.gov/newsroom/press-releases/cms-increasing-o...