Walmart and its membership store Sam’s Club will test out Uber and Lyft for grocery deliver service, the supermarket giant announced today. The partnership is a pairing of the biggest names in ride-hail with the biggest name in big-box supermarkets, and could signal a massive change in brick and mortar delivery.

The decision to outsource delivery service isn’t entirely new for Walmart. In March, Walmart launched a “very quiet” Sam’s Club pilot program to test product delivery using the startup delivery service Deliv. With Uber and Lyft, however, only groceries will be delivered.

Where It Will Be Tested

The service will start in Denver and Phoenix in one or two weeks. It’s clearly still in an experimental stage, and Walmart hasn’t decided which service it would like to use yet. In one market Uber will be used, and in the other Lyft will be used, according to TechCrunch. It hasn’t been stated which city will get which service.

How It Will Work

Walmart customers will be able to pick out their groceries on Walmart’s grocery webpage. An option for delivery will be offered at checkout, and the buyer can pick a window of time that works best.

“Our personal shoppers, highly-trained Walmart associates, will carefully select and prepare their order,” Walmart explains in a press release. “Then, our team may request a driver from one of these services (meaning Uber and Lyft) to come to the store, pick up the customer’s order, and take it directly to the customer’s location. It’s all seamless to the customer.”

Walmart lets the customer know that their groceries will be delivered by a ride-hail driver. When it gets there, the person doesn’t need to worry about tipping or payment because Walmart handles the $7 to $10 standard delivery charge.

For now, Uber and Lyft deliveries will only include groceries. Deliv in Miami will still delivery any product from Sam’s Club, however.

“We’ll start small and let our customers guide us,” Walmart states, “but testing new things like last-mile delivery allows us to better evaluate the various ways we can best serve our customers how, when and where they need us.”

What This Means For Drivers

After Walmart employees pick out the products the person ordered online, a team member will request an Uber of Lyft driver through the respective app just as a person does when requesting a ride.

Drivers are informed that it is a grocery delivery when they receive the order.

Ride-Hail Moves Beyond Passenger Transportation

Ride hail services have experimented with food delivery in the past. Uber launched UberEATS in select markets last year. UberEATS was run off of a separate app and delivered food from partnering restaurants and businesses.

Uber also experimented with on-demand food orders with a service called Instant Delivery, but the service had trouble staying profitable. Uber stopped delivering on-demand food in New York City in April.

The major partnership with Walmart offers a new opportunity for the two major ride-hail services to move beyond just transporting people. It fits in Uber’s and Lyft’s overall mission of mobility, as people who could not previously get to the supermarket can essentially have the supermarket come to them.

A host of other grocery deliver services like Instacart, Peapod, Shipt, Amazon and Google are already available. Walmart’s choice to outsource to established ride-hail companies with an established fleet will likely ease the transition into a crowded delivery market.