Flight crew unions have fought hard for the change, saying that flight attendants are heavily fatigued and overworked after shifts as long as 14 hours.
Airlines were told of the coming rule changes by the Federal Aviation Administration last week, a source familiar with the policy said.
Current FAA rules mandate that in most cases, an airline provides a flight attendant a nine-hour rest period after being on duty 14 hours or less.
Late last year, the FAA opened public comment on a proposed regulatory change that would increase the rest period to 10 hours between shifts.
The change was first approved by Congress in 2018 but was not put in place by the Trump Administration.
Last week, House Transportation Committee Chairman Peter DeFazio (D-Oregon) called seeing the rules completed a priority before his upcoming retirement.
The FAA is holding a news conference Tuesday at Reagan National Airport with Acting Administrator Billy Nolen for what it says is a "major announcement."
The FAA declined CNN's request for comment.
Rough time for flight attendants
With a surge in demand as pandemic restrictions eased, 2022 has been hard on flight attendants.
The flight attendants say situations like these, along with unpredictable schedules, wreak havoc on crew mental and physical well-being.
It's not just in the United States where flight attendants say they are being run ragged.
"Sickness levels have gone through the roof, fatigue levels have gone through the roof, not because [flight attendants are] rejecting or they're protesting in any way. It's just that they can't cope -- they just can't cope with the constant changes," says British flight attendant Kris Major.