Prime members can pay $9.99 per month for unlimited grocery delivery from Whole Foods and Amazon Fresh on orders over $35.
The service is currently available in Denver, Sacramento, and Columbus.
Amazon hopes the subscription will drive bigger and more frequent food orders among Prime members.
Amazon has adjusted its fee-free delivery threshold for Fresh and Whole Foods orders in recent years.
The company introduced a $10 service fee for Whole Foods delivery orders to Prime members in 2021.