Returning to SEPTA in the “yellow” phase of reopening? Don’t forget your face mask.

On Monday, the transportation authority will require riders to wear face coverings to protect against the spread of the coronavirus, it announced Friday. The move comes alongside enhanced cleaning efforts and social distancing measures, including rider limits, already in place.

“It’s a continuation of what we’re doing,” SEPTA General Manager Leslie S. Richards said Friday. “We want to be clear that this policy is not going to be enforced by SEPTA police, but we are going to remind customers who don’t have face coverings that they are required to wear one.”

SEPTA will make some masks available to riders who need them at select customer service locations, Richards said, but any type of covering is acceptable, including bandannas.

Facial coverings have been a sensitive subject for the authority. SEPTA reversed a short-lived requirement after a viral video showed a man being dragged off a SEPTA bus for allegedly not wearing a mask in April.

SEPTA has since “strongly urged” riders to wear coverings. Most riders have been wearing masks, Richards said.

“When we started with urging facial coverings, it was a new thing,” Richards said, “and now it’s part of the new norm.”

Face coverings are encouraged but not required on PATCO, said Delaware River Port Authority spokesperson Mike Williams. Amtrak and Greyhound began requiring face masks last month.

The requirement follows federal and local health and safety guidelines. The Centers for Disease Control and Prevention recommends wearing coverings to slow the coronavirus’ spread and says they should be worn “in public settings where other social distancing measures are difficult to maintain.”

SEPTA is bracing for a boost to ridership as COVID-19 restrictions lift. The region and its suburbs entered yellow Friday, where retailers, day-care centers, and offices are able to reopen. Most transit service has resumed, but Regional Rail continues to run on a limited schedule.