New York City is included among the new locations.
The membership-based retailer said it will be administering shots "as soon as they are available."
But, being a Costco member doesn't guarantee you'll be able to sign up for the shot.
Costco said it only has a limited number available, and it would follow eligibility guidelines in each state.
"Costco is firmly committed to helping protect the health and safety of our members and employees, and to serving our communities," the company wrote in its announcement.
Manhattan, Brooklyn, Queens and Staten Island stores are set to receive the vaccine once available.
Costco asked its customers to not contact their local store pharmacy to schedule appointments. Instead, customers should visit its website.
The company said they expect to administer primarily Moderna vaccines.
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