Costco Wholesale Corp. says it has revised its policy starting Monday to require all members, guests and employees entering its stores to wear a face mask or face shield.

In a letter to Costco members on Tuesday, Costco President and CEO Craig Jelinek said entry to Costco will be granted only to those wearing a face mask or face shield, with the exception of children under the age of 2.

Although Costco has had a face mask policy for its stores in effect since May 4, it has allowed members with medical conditions to enter without a mask. This will no longer be the case, said Jelinek.

“If a member has a medical condition that prevents them from wearing a mask, they must wear a face shield at Costco,” wrote Jelinek. “This updated policy may seem inconvenient to some, however we believe the added safety is worth any inconvenience. Our goal is to continue to provide a safe shopping environment for our members and guests, and to provide a safe work environment for our employees.”

Members and guests must wear a face mask that covers their mouth and nose, Costco said in its COVID guidelines. Furthermore, the use of a face covering should not be seen as a substitute for social distancing.

For members unable to wear a mask or face covering, delivery options are available via Costco.com, although not all products might qualify for shipping to Hawaii.