The announcement that Buffett, JPMorgan CEO Jamie Dimon, and then-Amazon CEO Jeff Bezos were teaming up to form an independent venture that would focus on healthcare for their US employees sent shockwaves through the healthcare industry.Healthcare stocks tumbled on the official news that Amazon had its eye on healthcare.In June 2018, Amazon said it bought the online pharmacy PillPack, a deal worth $750 million. The acquisition clarified how Amazon planned to disrupt the healthcare industry, by bringing its massive delivery capabilities to prescription drugs.In June 2018, the joint venture selected Dr. Atul Gawande, a surgeon and writer, to serve as its CEO. By March 2019, the venture had an official name: Haven.At the time, the pilot was limited to employees in the Seattle area.After two years on the job, Gawande stepped down to focus more on pandemic work. He stayed on as Haven's chair.Two years after buying PillPack, Amazon unveiled its Amazon Pharmacy service — again sending healthcare stocks tumbling. As part of the service, Amazon offered discounts to Prime members and free delivery.Amazon Care spent its first year providing care for Amazon employees. Insider's Dodge reported that it planned to bring the primary-care service to other companies and that Amazon had started pitching the service to companies such as Zillow.Haven struggled with a lack of focus, it didn't get much support from Amazon, and its one big project failed, Insider, Stat, and The Information reported.Throughout 2021, Amazon geared up to launch Amazon Care for its employees and other companies across the US. Its first client was Precor, a fitness company owned by Peloton. Amazon tried to win over insurers but struggled to get them on board.Amazon considered other ways to grow its healthcare footprint that year, including setting up physical pharmacies to complement its online prescription business.Amazon's announced acquisition of the primary-care company One Medical for $3.9 billion is its third-biggest acquisition ever. Industry leaders told Insider it showed that Amazon was betting big on care delivery as a way to supercharge its growth into healthcare.One month after striking a deal for One Medical, Amazon announced its plan to shut down Amazon Care, its homegrown care service. In a memo, Amazon said the decision came after months of consideration.Employees told Insider's Dodge that Amazon got in its own way when trying to take on the healthcare industry, which led to the fall of Amazon Care.In the wake of Amazon Care's shutdown, Insider reported the tech giant was quietly working on a project code-named Katara that planned to treat common conditions like hair loss online. Two months later, Amazon publicly launched the project, called Amazon Clinic.At an internal conference, Amazon scientists and engineers discussed ways to use artificial intelligence and machine learning to help improve medical research, Insider's Kim reported. Taha Kass-Hout, its chief medical officer at the time, was involved in the discussions.In January, Amazon announced its latest healthcare venture, RxPass. The program allows Prime members to get many common generic medicines for just $5 a month.