Amazon today announced that Prime Now, its one-hour delivery service, is available in Baltimore and Miami.

The service had previously only been available for Amazon Prime members in parts of New York City since launching in December 2014. Subscribers who pay the annual $99 membership can use the Amazon Prime Now app to order a wide range of items for rapid delivery in areas where it operates.

The ability to deliver items at an accelerated pace is the result of Amazon’s continued expansion of warehouses and logistics facilities, coupled with software and operational efficiencies.

“Since launching, we’ve seen high demand on everything from essentials like water and paper towels to more surprising deliveries like getting a customer a hard-to-find, top-selling toy in 23 minutes,” said Dave Clark, Amazon’s senior vice president of worldwide operations, in a press release.

According to Amazon, Prime Now orders can be made between 8 a.m. and 10 p.m., seven days a week. While two-hour delivery is free, Prime members still must pay an extra $7.99 to secure a one-hour delivery window.

Amazon says the Prime Now service will be “available in select zip codes.” Customers can download the app and get a notification when it becomes available in their neighborhood.

Finally, the company said it intends to rollout the service to new cities throughout 2015.