The move comes as ridesharing companies struggle to maintain revenues with millions of people worldwide under social distancing orders from public health authorities.
Lyft has previously committed to distributing masks to its more than one million drivers, focusing on cities where masks are required by law, said Angie Westbrock, head of global operations, although she declined to say how many masks had been or would be distributed.
"A really important component of this policy is that it's not just for drivers," Westbrock said. "This policy requires passengers to also certify that they're going to comply with this health safety policy and that they'll also wear a mask."
Passengers are also asked to leave the windows open when possible, and not sit in the front seat of cars.
Masks and cleaning supplies for drivers will be distributed through Lyft's hubs, some of which will reopen for this purpose, Westbrock said.
Uber Technology Inc, Lyft's main competitor, has said they will implement technology that will require drivers to submit a photo of their face to confirm that they are wearing the mandatory mask.
Unlike Uber, Lyft only operates in the United States and parts of Canada.