The discount retailer has had a face-mask policy in effect since May, but those who couldn’t wear masks due to medical conditions were exempt.
This "will no longer be the case," Costco President and Chief Executive Craig Jelinek wrote in a letter to the Issaquah, Wash., membership-based retail chain's customers this week.
Costco will allow entry only to those wearing face masks or face shields. Children under 2 are exempt.
Last month, Costco started to sell coronavirus testing kits on its website. Priced at $129.99 and $139.99, the retailer's Covid-19 Saliva PCR Test Kits claim to have the most accurate sensitivity and specificity currently on the market, according to the website.
The self-administered saliva tests come without a nasal swab, which has been widely used for testing in the country.
These tests aren't invasive and can easily be done at home, which helps protect health care professionals from being exposed.
Customers can get their results within three days of the lab receiving the sample for diagnostic testing.
Costco said net sales for the five weeks ending on Oct. 5 were up 17% from a year earlier at $16.84 billion, while comparable-store sales surged by a much better-than-expected 15.5%.
Jim Cramer spoke about the retailer on Wednesday. Cramer sees a key reason to hold rival Walmart instead of Costco. He explains his reasoning to the November meeting of the Action Alerts PLUS investing club.