Get all the latest news on coronavirus and more delivered daily to your inbox. Sign up here.
Starting Monday, all U.S.- based employees, including within company clubs, distribution and fulfillment centers and corporate offices, will be required to comply with the regulation, according to a memo from Walmart U.S. CEO John Furner and Kath McLay, the CEO of Sam’s Club, a division of Walmart Inc.
Customers and members are also "encouraged" to wear face coverings while they shop.
Both executives cited guidance from state and local public health officials, the Centers for Disease Control and the company's chief medical officer.
"We have evolved our policy on face coverings from optional to mandatory as public health guidance has shifted," the memo read. "We hope this step will promote safety and consistency across all of our facilities and be of comfort to our customers and members."
Local governments around the nation, including hot spots like New York, are requiring residents to wear face masks in public areas where social distancing is not possible.
The measures follow recent studies from the Centers for Disease Control and Prevention indicating that a "significant portion of individuals" with the virus can lack symptoms and even those who develop symptoms can transmit the virus before showing symptoms.
"With this knowledge, we believe it is simply in everyone’s best interest to use masks or face coverings to curb the spread of this disease," the memo continued.
The company cautioned that this step does not "guarantee against the spread of this virus" nor does it replace other measures.
Employees are reminded, whether at work or elsewhere, to continue to practice social distancing, washing their hands with soap for at least 20 seconds, and to stay home if they have a temperature of 100 degrees or higher.
Last month, Walmart announced it was implementing temperature checks for all associates before the start of their shift and that it was making masks and gloves available for associates who want to wear them.