At Costco, face coverings will still be required across Illinois until Gov. J.B. Pritzker changes the state's mask mandate. However, according to Costco's website, masks do not need to be worn if a shopper is fully vaccinated in stores if the local jurisdiction does not have a mandate in place. Costco noted customers do not need to provide proof of vaccination, but asked for members' "responsible and respectful cooperation with this revised policy." Face coverings are still required in Pharmacy, Optical and Hearing Aid areas. "Costco continues to recommend that all members and guests, especially those who are at higher risk, wear a mask or shield," the website read.