• Amazon said Wednesday it will soon stop requiring face masks for fully vaccinated workers inside warehouses, except where required by law.
• To verify that workers are vaccinated, Amazon will require them to upload their vaccine information to an internal employee portal.
• Amazon started the push to vaccinate its workers in March, when it began rolling out on-site vaccination clinics at some of its warehouses.

Amazon said Wednesday it will soon stop requiring face masks for fully vaccinated workers inside warehouses, except where required by law.

Starting Monday, fully vaccinated operations employees in the U.S. will no longer be required to wear a face covering at work unless it is mandated by state or local regulations, according to a notice Amazon sent to workers that was obtained by CNBC.

Amazon confirmed to CNBC that it's updating its mask policies for fully vaccinated workers.

Amazon said in the notice to workers that it considers them to be fully vaccinated once it has been 14 or more days since their final vaccine dose. Workers must also have a copy of their vaccine card, the company said.

"A HUGE thank you to everyone who has and continues to prioritize our Covid-19 safety measures," the company said in the notice to workers. "The last 14 months have not always been easy, but your dedication continues to be appreciated by leaders and customers across the country. We cannot wait to see your smile."

To verify that workers are vaccinated, Amazon will require employees to enter their vaccine information into an internal employee portal, called "A to Z." Fully vaccinated employees will receive a green check mark on screen, which they then show as proof as they enter their site at the start of their shift.

By early June, Amazon said it will provide workers with a green check mark sticker that they can add to their badge, signifying they're fully vaccinated and allowing them to enter work without a face covering or verifying their vaccination status. By mid-June, Amazon said, it will ask workers to upload a picture of their vaccine card to the internal portal.

All other Covid-19 safety protocols will remain the same, Amazon said. Last March, Amazon began taking certain safety precautions inside warehouses, such as instructing employees to wash their hands, use hand sanitizer and practice social distancing.

Amazon joins a growing list of retailers and restaurants that have eased mask requirements since the Centers for Disease Control and Prevention said earlier this month that fully vaccinated people don't have to cover their faces indoors anymore. Costco, Walmart, Chipotle, Target and Starbucks are among several companies that have updated their mask requirements. Home Depot, Gap and Ulta Beauty are among those that said they would maintain their safety precautions for the time being.

Amazon hasn't required its front-line workers to get vaccinated, but it has nudged employees to get a coronavirus shot by offering them a bonus of up to $80. Additionally, it has told new hires that they will get $100 for showing proof of vaccination.

Amazon in March began rolling out on-site vaccination clinics at warehouses in Missouri, Nevada and Kansas. Since then, Amazon said, clinics have opened in more than 250 warehouses across the U.S. and Canada, covering more than half a million front-line warehouse and delivery workers.