Amazon will acquire One Medical as part of its effort to expand into the health care business, the company said Thursday. One Medical runs a chain of more than 150 primary care clinics in over a dozen US cities and offers online and mobile services. Amazon will pay $18 a share for the company, putting the deal's value at about $3.9 billion. 

The acquisition, which must be approved by regulators and One Medical shareholders before it's final, will greatly expand the primary care services Amazon is already offering through its Amazon Care brand.

"We love inventing to make what should be easy easier and we want to be one of the companies that helps dramatically improve the healthcare experience over the next several years," senior vice president of Amazon Health Services Neil Lindsay said in a statement. 

One Medical offers services to individual subscribers as well as workers who receive its benefits from employers. It aims to speed up access to care with round-the-clock virtual care for patients and quick appointment booking. Amazon Care currently provides medical care in eight cities, including the home of Amazon's offices in both Seattle and Arlington, Virginia, and it's slated to expand into New York, San Francisco and other major cities. 

Amazon's "presence becomes much stronger as One Medical's services reach nearly 800,000 members across 25 US markets," said Insider Intelligence analyst Rajiv Leventhal, who added that the acquisition will make Amazon a close competitor of CVS Health and Walgreen's efforts to expand into primary care. 

Currently, Amazon Care patients can receive in-home visits for flu and COVID-19 testing, vaccinations, preventive care, prescriptions and treatment for a range of conditions and book online appointments.

After launching Amazon Care in 2019, the company followed up in 2020 by launching its own online pharmacy. Amazon Pharmacy fulfills prescriptions for those with or without insurance, and delivers them to customers' homes. Prime members receive special savings and free two-day shipping.