More than 200,000 payment locations in the U.S. are equipped to accept so-called contactless payments, including Apple Pay. Smaller merchants tend to be among the several millions that don't have the required equipment yet.
Apple said it has worked with several retailers to make sure most of their stores, if not all of them, were ready at Monday's launch: Aeropostale, American Eagle Outfitters, Babies R Us, BJ's Wholesale Club, Bloomingdale's, Champs Sports, Chevron and Texaco retail stores including ExtraMile, Disney Store, Duane Reade, Footaction, Foot Locker, House of Hoops by Foot Locker, Kids Foot Locker, Lady Foot Locker, Macy's, McDonald's, Nike, Office Depot, Panera Bread, Petco, RadioShack, RUN by Foot Locker, SIX:02, Sports Authority, Subway, Toys R Us, Unleashed by Petco, Walgreens, Wegmans and Whole Foods Market.
Apple also said that the following merchants plan to add support by the end of the year: Anthropologie, Free People, Sephora, Staples, Urban Outfitters and Walt Disney Parks and Resorts.
For online payments, Apple said the following merchants have apps ready for Apple Pay: Chairish, Fancy, Groupon, HotelTonight, Houzz, Instacart, Lyft, OpenTable, Panera Bread, Spring, Staples, Target and Uber.
Others expected by year's end include: Airbnb, Disney Store, Eventbrite, JackThreads, Levi's Stadium by VenueNext, Sephora, Starbucks, StubHub, Ticketmaster and Tickets.com.
Of course, Apple's retail stores and the Apple Store app will also take Apple Pay.
Apple Pay launched in the U.S. on Monday and requires an iPhone 6 and 6 Plus with iOS 8.1 for in-store and in-app payments. The iPad Air 2 and the iPad Mini 3 out later this week will be able to make in-app payments only.