Amazon's pharmacy business will expand its same-day delivery prescription service to about 4,500 cities and towns in the U.S. by the end of this year, adding nearly 2,000 new communities to the network.

The expansion covers states including Idaho and Massachusetts, the company said on Wednesday.

Amazon launched pharmaceutical delivery in 2018 through its acquisition of PillPack. In October, it partnered with WeightWatchers to deliver medications including injectable GLP-1 obesity treatments for the weight-loss management firm's members.

It also began filling some prescriptions for common medications in December at electronic kiosks in its One Medical primary care locations.

One Medical, a national primary care provider Amazon acquired in 2023, allows patients to access primary and urgent care for an annual subscription fee of $199.