Published on September 09, 2025

Mark Vortherms and Mara Hermiston, DO

Next Generation of Avera Medical Group Leaders Build on Strong Legacy

For the next generation of Avera Medical Group leaders, success will mean building upon a legacy of excellent culture and strong physician engagement.

New dyad leaders for Avera Medical Group are Mara Hermiston, DO, Chief Medical Officer, and Mark Vortherms, Chief Administrative Officer. They were named after a restructure that allows the former team, Kevin Post, DO, and David Flicek, to focus solely on their respective roles as Chief Medical Officer and Chief Operating Officer for Avera Health.

As Avera is rapidly growing and expanding, these leaders are focused on maintaining the culture, which is central to identity. These new leaders also recognize the role a health system has in the profession of medicine, listening to the highly trained physicians about what fulfills them.

“Avera is extremely blessed with a highly talented, highly engaged medical group, and physicians and advanced practice providers who very much believe in the mission of Avera,” Vortherms said. This includes innovation to improve access to care both in Sioux Falls and at rural locations, and a service line model that has elevated clinical quality across the footprint.

Avera Medical Group encompasses 1,330 clinicians and 200 primary and specialty care clinics in 100 communities. “Our physician retention rate is 96%; the national turnover rate is two to three times higher than ours. Our physician engagement scores are in the top decile nationally,” Vortherms said. While Avera Medical Group has grown from 876 physicians and advanced practice providers (APPs) to 1,330 over the past 10 years, more than 40% of current physicians have been with the group throughout that growth. “There are physicians that have sought us out because of our special and unique culture,” Vortherms said.

Value of Physician Leadership

“Physician leadership is important at Avera. Our voices are respected, listened to and acted upon,” Hermiston said. “In addition, Avera puts patients first in our decision-making, which is important to physicians. Our clinicians are incredibly passionate about the work they do and care they deliver to the patient and our communities, and we want to be able to support that by equipping and empowering them,” Hermiston said.

“At Avera, physicians lead and patients come first – it's that straightforward. When clinical judgment drives our decisions, we can focus on what really matters. This patient-centered approach isn't just a catch phrase here at Avera – it's who we are,” said Benson Hsu, MD, Avera pediatric critical care specialist.

Hilary Rockwell, MD, another Avera physician whose career has taken a leadership turn, serves as Regional President of Avera Queen of Peace Hospital in Mitchell. “Physicians bring an essential clinical perspective to administrative decision-making. They provide insight into the affect operational decisions will have on patient care and physician satisfaction. Our physicians are on the front line, not only in patient care but also in strategic initiatives by driving clinical excellence, patient experience and so much more.”

Balanced Perspectives in Leadership

Hermiston comes from a background in family practice in Spirit Lake, Iowa, and still continues to see patients in a clinical setting. While learning the rewards of a rural practice, she also learned the challenges, including the isolation that can develop and need for feeling supported with specialty expertise.

Her preparation for leadership includes pursuing an MBA to complement her medical degree, as well as participating in Avera’s physician leadership development programs.

Vortherms’ career at Avera has spanned 25 years, most recently as Vice President for Primary Care. He played a major role in opening numerous clinics, including Avera Family Health Centers on Marion Road and at Dawley Farm that are home to the first freestanding emergency departments in the state.

Health Care as a Team Sport

Avera pairs administrators with physicians to form dyad teams, bringing a balanced perspective to Avera Medical Group, amongst senior leadership and for each of the 14 service lines.

Service lines are where groups of similar physicians can collaborate on quality initiatives, clinical best practices, patient experience, partnership opportunities and other areas.

Service line physician leaders are always looking into the literature to stay on the leading edge of their specialties and ensure best practices at each location across the Avera footprint. “Health care is a team sport. It’s important to be able to pick up the phone and have a conversation with a colleague. Service lines foster that collegiality,” Vortherms said.

Avera prioritizes physician well-being through its Light program. One practical goal is lifting the burden of administrative tasks, so physicians and advanced practice providers can spend more time in direct patient care. “Using ambient AI for tasks such as dictation has decreased the amount of time physicians spend charting,” Hermiston said. “For physicians who went into medicine to take care of patients, not having to worry about dictation brings back some of that joy.”

Avera recently brought its OB/GYN and pediatrics service lines together as one Women’s and Children’s Service Line to help support integration between these separate but related services. This approach will be important as Avera prepares to open the new six-story tower on the Avera McKennan campus to house a center of clinical excellence for women's and children's services. “This center will be in Sioux Falls, but will help to support the hundreds of clinical team members who care for women and children across our footprint,” said Vortherms.

“There’s great value in bringing a physician perspective to the table as we’re looking to what physicians need and value, while also being sensitive to operational challenges that arise,” Hermiston said.

“When we see the work our physicians, APPs and staff do, day in and day out, it makes us really proud to be part of this team,” Vortherms said.

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