Delta and United are doubling down on mask requirements, calling out phony medical exemptions and banning passengers

• Delta and United Airlines have announced new, stringent enforcement of rules requiring passengers to wear masks on board flights due to the coronavirus.
• Delta will require anyone claiming a medical exemption to speak with a medical professional, while United extended its requirement to all parts of the airport.
• Both airlines said they would ban passengers who refuse to cooperate.

Delta Air Lines and United Airlines are doubling down on requirements that passengers wear masks on flights, adding teeth to the rules and working to close loopholes some passengers have exploited.

United on Wednesday announced that it was expanding its on-board mask requirement to cover all parts of the airport, including at check-in counters, kiosks, lounges, baggage drop and claim areas, and at gates.

The airline also said that it was cracking down on non-compliant passengers who falsely claim that they can not wear a mask due to a medical condition. Passengers with medical exemptions must contact the airline before their flight, or speak with a customer service agent at the airport before boarding, to document the exemption. Otherwise, passengers must wear a mask, or will not be allowed to fly.

Passengers who violate the policy either in the airport or aboard a plane risk being banned from the airline for an unspecified period of time. Children under the age of two are exempted.

"The most important thing any of us can do to slow the spread of the coronavirus is to simply wear a mask when we're around other people," United CEO Scott Kirby said in a press release. "A mask is about protecting the safety of others, and I'm proud of the aggressive and proactive steps United Airlines has taken to ensure people are wearing a face covering in the airports where we operate and onboard the aircraft we fly."

Delta went a step further with a new policy to formalize — and thus limit — medical exemption claims.

Starting this week, the airline will no longer simply ask passengers to provide advance notice that they will claim such an exemption. It will require passengers who refuse to wear a mask and claim a medical exemption to complete a "Clearance-To-Fly" process at the airport.

"If you require this exemption, please arrive early to complete the process during check-in and avoid missing your flight – this process can take over one hour," the airline says on its website.

The process will include a telehealth consultation with a medical professional through the University of Pittsburgh and health service StatMD, Delta CEO Ed Bastian said on NBC's "Today" on Wednesday.

"Any false claims of a disability or health condition to obtain an exemption from wearing a mask or face covering may result in the suspension of travel privileges on any Delta flight for the duration of the mask/face covering requirement," the airline said.

The consultation will be a private phone call, according to The Points Guy, facilitated by airport staff. Pending the outcome, passengers will either be allowed to fly maskless, or will be rebooked for a later flight or given a refund.

The airline has already banned more than 100 people for refusing to comply with the mask requirement, Bastian said. "If you board the plane and you insist on not wearing your mask, we will insist you don't fly Delta," Bastian said.

United also said on Wednesday that it would start flying larger planes, where possible, to allow passengers more room to spread out and distance. About 15% of the airline's flights are expected to fly with more than 70% of seats filled, the airline said.

United and American Airlines have faced criticism in recent weeks for filling planes to capacity, not allowing for social distancing. Delta capped capacity on its planes at about 60%, and said it will continue blocking middle seats through at least September.

Earlier this month, United Chief Communications Officer Josh Earnest said that blocking the middle seat is "a PR strategy. That's not a safety strategy." A recent statistical study by MIT showed that filling middle seats roughly doubles the risk of catching COVID-19 on a plane.

During a recent Senate hearing, Anthony Fauci, the top infectious diseases official at the US National Institutes for Health, criticized airlines that did not block the middle seat. "Obviously, that's something that is of concern," he said. "Avoiding crowds, staying distant, and when in a situation like that, wear a mask — I think in the confines of an airplane, that becomes even more problematic."

Robert Redfield, the director of the US Centers for Disease Control and Prevention, agreed.

"I can tell you that when they announced that the other day, obviously there was substantial disappointment with American Airlines," he said.