Walmart is leveraging its huge store network to target last-minute shoppers—and by its account, there are plenty of them.

The discounter, which said 84% of Americans are still shopping for the holidays, is making a big push for its same day in-store pickup service. It’s made more items eligible for the service than ever before. Also, customers will be able to shop for qualifying items, notated with “Free Pickup Today,” online until 4 p.m. local time on Dec. 23. The items can be picked up in stores until 6 p.m. on Dec, 24.

Ninety percent of Americans live within 10 miles of a Walmart store, making its pickup…