Amazon.com is turning to Prime members to bolster its healthcare business, an industry where the company has sought to expand for years. 

The tech giant on Wednesday revealed plans to offer its millions of Amazon Prime subscribers a low-cost annual membership to One Medical, the primary-care business Amazon purchased for $3.9 billion earlier this year. Amazon says Prime subscribers can now become One Medical members for $9 a month, or $99 a year. The typical cost to become a One Medical member is $199 annually.