In March 2020, the Centers for Disease Control under Trump invoked a provision in U.S. health law (Section 265 of Title 42) that allows authorities to prohibit foreigners from entering the country when there is a risk of a disease being introduced. Over the course of the pandemic, Title 42 has blocked more than 1.7 million attempts by migrants and asylum-seekers to cross the border.
After taking office, the Biden administration continued this policy, even appealing court decisions to end the practice. However, earlier this month, Biden's CDC announced that it would be terminating Title 42, effective May 23, 2022, "after considering current public health conditions and an increased availability of tools to fight COVID-19." Officials anticipate a surge of more than 170,000 migrants across the border after Title 42 is lifted.
The CDC continues to require masking on most modes of public transportation.