The No. 2 executive at Haven, the healthcare company backed by Amazon, JPMorgan and Berkshire Hathaway, has left nine months after joining the fledgling firm.

Chief Operating Officer Jack Stoddard departed April 30 for personal reasons, a Haven spokesperson confirmed. The company hasn’t named his replacement.

“Jack played an important role in the early stages of Haven, but we understand his decision to leave the company for family reasons,” a spokesperson told CNN Business. “We want to thank him for all of his contributions.”

Stoddard joined Haven in September 2018 from Comcast, according to his LinkedIn. Prior to that, he held various roles at other healthcare companies, including UnitedHealth Group.

The Boston-based company was formed in January 2018 by Jeff Bezos, Warren Buffett and Jamie Dimon.

Haven aims to make primary care easier to access, insurance benefits simpler to understand and use and prescription drugs more affordable, the website says. It seeks to harness data and technology to make the overall health care system better. It notes that solutions may take time to develop.

The three companies said they would work together to give their combined 1.2 million employees and dependents better health care choices and bring down prices.

It named Dr. Atul Gawande, a renowned surgeon and writer, to be its CEO in June 2018.