Dr. Steven Walerstein has abruptly left his post as chief medical officer at NuHealth.
Walerstein resigned Thursday, said Dr. Victor Politi, chief executive of NuHealth, which includes Nassau University Medical Center in East Meadow.
Politi said he couldn't discuss the circumstances surrounding Walerstein's departure, but noted: "It was mutual."
The chief executive said someone on the staff will serve as acting chief medical officer of the public health benefit corporation, which includes NUMC, A. Holly Patterson Extended Care Facility and five clinics that serve the poor, but he declined to name the person.
Politi said he would start a search both internally and externally for a permanent replacement.
Walerstein, who became chief medical officer more than eight years ago, declined to comment on his departure or his plans. But he praised the staff at NuHealth.
"It has been an honor and privilege to serve as the chief medical officer," he said. "Thanks to the efforts of the outstanding staff of medical professionals, we were able to elevate the quality and depth of services offered to our community, and I sincerely hope that the honors and accolades received over the last years continue to accumulate."
Politi said he wished Walerstein "the best of luck going forward."
Walerstein had worked closely with Arthur Gianelli, who suddenly resigned in November as NuHealth's chief executive. Nassau County Executive Edward Mangano, a Republican, said that Gianelli, appointed to the post by then-County Executive Tom Suozzi, a Democrat, in 2006, was asked to resign so the county could search for new leadership.
In January, Mangano named Politi, Nassau's acting police commissioner, to replace Gianelli.
A native of Elmont and graduate of Albany Medical College, Walerstein first came to NUMC in 1999 as chairman of the department of medicine. He left in 2002 to go to New York Methodist Hospital in Brooklyn as associate medical director, returning to NUMC in 2005 as chief medical officer.