The administration plans to give community clinics 50 million tests for the poor and uninsured, and Americans can also get a free test at a federally supported testing site. But the Biden administration’s ability to make it rain rapid tests remains hampered by the peculiarities of American health care, which is more complicated and privatized than the systems in the U.K. and many other rich countries. Still, the White House’s testing coordinator, Carole Johnson, seemed to imply that the administration is working to expand the types of people who can get reimbursed for the tests.