Randy Phelps resigned Wednesday as administrator of The Memorial Hospital. He submitted his letter during a closed-door session after the board's regular meeting.
Board president Sue Lyster said Phelps' resignation was voluntary and will come as a shock to staff members.
"He said he felt, in the best interests of the hospital, it was time for a change," she said.
She said the hospital's management company advised the board to discuss the resignation in executive session.
Phelps has worked at TMH for 18 years. He's seen the hospital through equipment upgrades, building projects and additions to services.
"Our laboratory and cardio-pulmonary equipment is the best money can buy," Phelps said in a press release. "I am proud of that achievement, and it always impresses visitors and doctors we're attempting to recruit that we have such great employees, medical staff and equipment."
When Phelps started in 1987, the hospital's annual gross revenue was $6 million. This year, it will exceed $24 million.
Phelps currently serves as chairman of the Colorado Hospital Association.
He was unavailable for comment Wednesday.
He also stated in the press release, "There comes a point in time when you have to say to yourself, 'this was worthwhile work and work well-done; however, it's time to take on a new challenge.'"
Lyster said the board also discussed in executive session, the hospital's strategies for moving forward.
She said the board is looking for the most seamless transition possible.
"We're losing a great administrator, but he has a great administrative team under him, so we hope this is a smooth transition," she said.
Quorum Health Care, the hospital's management company, will provide the hospital with an interim administrator by Aug. 8. Phelps will work until that time and a few days beyond.
Lyster said the hospital board will form a hiring team made up of board members and members of the medical community. They will define what they want in an administrator and provide that to Quorum, which will provide candidates for the position.
"That process could take anywhere from 90 to 120 days," Lyster said. "I'm optimistic that we will find an excellent candidate.
"I think the change is good," Lyster said. "Sometimes change is hard, but this will be good."
She said the hospital will stay on track in its plans to build a partial replacement hospital as well as continuing to provide quality care.