Amazon on Thursday agreed to buy healthcare provider One Medical for approximately $3.9 billion, expanding the e-commerce giant's virtual healthcare and adding brick-and-mortar doctors' offices for the first time. 

The online retailer will acquire One Medical for $18 per share in an all-cash transaction, including One Medical's net debt. The deal would combine two relatively small players as Amazon continues a years-long march into U.S. healthcare, seeking to grow at a faster pace. 

Amazon first piloted virtual care visits for its own staff in Seattle in 2019 before offering services to other employers under the Amazon Care brand. It likewise bought online pharmacy PillPack in 2018, underpinning a prescription delivery and price-comparison site it later launched. 

"We think healthcare is high on the list of experiences that need reinvention," said Neil Lindsay, senior vice president of Amazon Health Services. The Seattle-based company has signaled its ambitions to improve and speed up care. 

The acquisition makes sense as the "blending of virtual and in-person care is core to both One Medical and Amazon Care's strategy," said Citi analyst Daniel Grosslight. 

(With input from Reuters)