The Transportation Security Administration announced Friday that travelers who do not wear a face mask could face fines of $250 to $1,500.
The TSA began requiring passengers to wear masks legally earlier this week, in accordance with President Joe Biden's executive order mandating face mask use during travel.
In a Friday update, the agency said it would implement civil penalties of a $250 fine for the first offense to up to $1,500 for repeat offenders.
The agency provided transportation system operators specific guidance on how to report violations so that they can issue the penalties.
In addition to fines, TSA previously said it may deny entry, boarding, or transport to those without a mask.
The U.S. mask order for travel implemented by Biden applies to airports and planes, ships, intercity buses, trains and public transportation, which all fall under the TSA's jurisdiction. Travelers from abroad must furnish a negative COVID-19 test before departing for the U.S. and must quarantine upon arrival.
"TSA will fully comply with the President's Executive Orders, CDC guidance and the DHS National Emergency determination to ensure healthy and secure travel across all transportation sectors. This will help prevent further spread of COVID-19 and encourage a unified government response," said TSA official Darby LaJoye. "As we continue to experience impacts from this pandemic, we are committed to this measure as the right thing to do for the TSA workforce, for our industry stakeholders and for passengers."
According to the agency's website, passengers who arrive at a checkpoint without a mask will be asked to put one on, if they refuse, they will not be permitted to enter the terminal and gate area. Those who refuse to wear a mask "may be subject to a civil penalty for attempting to circumvent screening requirements, interfering with screening personnel, or a combination of those offenses.