Amazon Pharmacy is expanding its same-day prescription drug delivery service. Starting Tuesday, the service will be available in New York City and the greater Los Angeles area.

Amazon said it plans to extend the service to more than a dozen cities by the end of the year.

“By bringing Amazon Pharmacy’s deliveries into our existing world-class logistics network, Amazon is building convenient service for the home delivery of prescription medications,” CEO of Worldwide Amazon Stores Doug Herrington said in a statement.

Already, Amazon Pharmacy operates its Same-Day Delivery service in Austin, Indianapolis, Miami, Phoenix and Seattle, using a variety of transportation methods, including electric bikes, electric vans and drones.

The Seattle-based retail behemoth said it is using new small-format locations that are stocked with common prescription medicines. One of the new facilities in Brooklyn stocks more than 12,000 medications that can be ordered at Amazon.com and fulfilled within minutes for delivery within hours, the company said.

Some Amazon fulfillment sites are also using robotic arms to help fill, label and send prescriptions in about 30 seconds.

To help fulfill prescriptions, Amazon is using machine learning and generative artificial intelligence to fact-check handwritten prescriptions and streamline their preparation. Amazon Pharmacy Director of Fulfillment Kelvin Downes said that every prescription is verified by a pharmacist to ensure it is the right medication, strength, dosage, quantity and address label before it is shipped.

The National Institutes of Health found that mail-order home medication deliveries make up 25% of pharmacy sales, with even higher take rates for people aged 65 and older. The NIH cited a growing body of research suggesting home delivery improves patients’ access to medications and adherence to medicines for conditions such as diabetes.