Amazon’s same-day delivery service is today seeing a notable expansion here in the U.S. The online retailer announced this morning that same-day delivery, which is available to members of its $99 annual Prime membership program, is now live in 11 more metropolitan areas and is rolling out to more neighborhoods in the markets where it already operates.

Specifically, Amazon is bringing same-day delivery to a number of medium-sized cities, like  Charlotte, Cincinnati, Fresno, Louisville, Milwaukee, Nashville, Raleigh, Richmond, Sacramento, Stockton, and Tucson. Meanwhile, it will also now be available in new areas in Central New Jersey, Dallas-Fort Worth, Los Angeles, and San Diego.

Consumers will need to login to Amazon to see if their particular address is supported.

In total, that means Amazon’s same-day delivery is now available in 27 metro areas across the U.S., or more than 1,000 cities and towns. That should worry competitors like Target and Walmart, who have been trying different ways to combat Amazon’s threat, ranging from ship-to-store programs, curbside pickup, and more. Walmart is even testing its own Prime competitor, “ShippingPass,” with no minimums and 3-day shipping.

With Amazon same-day delivery, Prime members place orders in the morning in order to take delivery by bedtime (i.e., 9 PM), and is available for a subset of Amazon’s inventory. Today, that includes over a million items across dozens of categories.

The service is one of now several tiers for faster deliveries Amazon offers. While the company’s Prime program offers free, two-day shipping on over 30 million items, it has been rapidly expanding its speedier delivery options in specific markets.

In addition to same-day, Amazon also offers Prime Now in over 25 metro regions, which offers tens of thousands of items for two-hour delivery from a dedicated mobile app. And through Prime Now, Amazon has also been expanding into restaurant deliveries and, in some markets, alcohol delivery.