Kowalski's Markets and Coborn's are following the lead of Target and Lunds & Byerlys and will require masks to help stem the spread of COVID-19.
A spokesman for Cub Foods and Jerry's Foods said it will mandate customer masks, according to Center for Disease Control guidelines, starting July 28.
Hy-Vee at this time will still encourage mask-wearing but not require it. Spokeswoman Christina Gayman responded in an e-mail that "Hy-Vee has no change at this time."
Employees at Hy-Vee have a mandatory mask rule. Last week, a Facebook group calling itself "Iowa Educators for a Safe Return to School" urged its members to contact Hy-Vee CEO Randy Edeker to require shoppers to wear masks.
Hy-Vee is against the tide. Also announcing a customer-mask mandate are Walmart, Sam's Club, Aldi and Whole Foods, joining Costco. Target's begins on Aug. 1.
Kowalski's Markets said disposable masks will be available for those without them.
"Our employees will be continuing to wear masks as well as practicing our already intense cleaning, sanitizing and restocking measures," said Kowalski's spokeswoman Laurie Bell.
Coborn's Inc. began its mandate Monday in its Coborn's, Cash Wise and Marketplace Foods and its liquor stores. Customers without a mask will be provided one.