Nathan Bomey

USA TODAY

You may never need to walk into a CVS store again — and that's just fine with the drugstore chain.

The retailer planned to announce Tuesday that it will allow customers to order most items using a mobile app and get their order delivered to their vehicle when they drive up to the store. The idea adds a twist to drive-through businesses — whether it has been banks, dry cleaners and, of course, myriad fast-food chains.

The service, dubbed CVS Express, was built on a mobile platform in partnership with Palo Alto, Calif.-based start-up Curbside, founded by the same entrepreneurs behind Apple's Find Your iPhone app. CVS invested an undisclosed amount in Curbside.

The curbside pickup service, integrated into the main CVS smartphone app, will come without any price markups, and CVS is promising to get orders ready within "about an hour."

CVS Express represents a new offering in the battle for customers in a get-in-now culture with same-day-delivery services on the rise. For example, it reflects a response to Internet giant Amazon's encroachment on the territory typically owned by convenience stores, such as beauty products, baby goods and groceries.

CVS stores in California, North Carolina and Georgia will offer the service immediately, followed by most of the retailer's 7,900 stand-alone U.S. locations by the end of the year. Urban locations without easy vehicle access are unlikely to get the service.

There are a few caveats. Prescription drugs must still be sold in-store or through a separate drive-through window. And only about 75% of the average CVS store's retail products will be available for order through the service.

CVS Pharmacy President Helena Foulkes said that in test markets repeat business was high.

"We think this is an answer for people who are looking for convenience and know and trust us," Foulkes said in an interview.

The trend fits comfortably within the buy-online-pick-up-in-store trend that is now available at many major big-box retailers — except at CVS you won't have to get out of your car.

Sam Cinquegrani, CEO of marketer ObjectWave, whose firm developed a similar curbside pickup service for Mexican pharmacy chain Farmacia San Pablo, said retail customers are demanding highly personalized experiences.

"It's a smart move on the part of the retailer, and I believe what that retailer will see, if it’s done correctly, is a customer that’s loyal to the brand," Cinquegrani said.

Still, there are a few hurdles for CVS, the nation's largest drugstore chain. For starters, Foulkes acknowledged that the CVS Express service will not be hooked up to the in-store inventory system.

So employees who will use smartphones to fulfill orders won't discover that items are out of stock until they walk through the aisle.

"The worst thing you can do is allow a customer to order something and then not have it when they come to pick up," Cinquegrani said. "They’ve got to be very careful."

Foulkes said that currently customers will be notified by text when they've ordered an item that's not available, offered a substitute item or provided their order without the item.

"Over time, this will put bigger burdens on us as we think about accuracy of inventory," she said.

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.