At CDC’s recommendation, TSA will extend the security directive for mask use on public transportation and transportation hubs for one month, through April 18th.
During that time, CDC will work with government agencies to help inform a revised policy framework for when, and under what circumstances, masks should be required in the public transportation corridor. This revised framework will be based on the COVID-19 community levels, risk of new variants, national data, and the latest science. We will communicate any updates publicly if and/or when they change.
Source: CDC