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About - Client


Dr. Ken Johnson

Dr. Ken Johnson, MD, FACEP is a highly accomplished medical professional with a wealth of experience and expertise in Emergency Medicine. Dr. Johnson embarked on his journey at Grandville High School, followed by academic pursuits at Miami University and Wayne State University School of Medicine.

His dedication to excellence led him to complete his residency in Emergency Medicine, laying the foundation for nearly three decades of compassionate care in the West Michigan region. Throughout his distinguished career, Dr. Johnson has been a stalwart presence in emergency departments, including Butterworth Hospital, where he has positively impacted countless lives.

Beyond the realm of medicine, Dr. Johnson finds joy and rejuvenation in various hobbies, including travel, reading, and outdoor pursuits like biking and hiking. A fervent enthusiast of spectator sports, he cherishes moments spent cheering on his favorite teams. Family holds a special place in Dr. Johnson's heart, as he shares a fulfilling life with his beloved wife Sheila and their four adult children. Known for his warm demeanor and genuine interest in others, he takes pride in forging meaningful connections with his patients, serving as a trusted resource and advocate on their health journey.


Dr. Steve Triesenberg

Dr. Steven Triesenberg is an internal medicine and infectious disease specialist with more than 30 years of experience. He aspires to provide personable, comprehensive care and enjoys helping patients meet their health goals at every stage of life. Dr. Triesenberg graduated from Michigan State University's medical school and infectious disease training at the University of Michigan.

Beyond medicine, Dr. Triesenberg has a passion for financial markets and investments, particularly in stocks. He finds joy in studying market trends and making informed investment decisions. Outside of work, he cherishes time with his beloved Boston Terrier named Moxie, and can occasionally be found relaxing in the sunshine.


Dr. William Baer

As the founding partner of Exponential Health, Dr. Baer has been practicing internal medicine for more than 25 years. Voted one of West Michigan’s Best Doctor's many years in succession, his skill set encompasses pharmacology, pharmacogenomics, genetics, and personalized medicine. Focused on longevity and disease prevention, he leads a unique concierge model rooted in comprehensive patient assessments and personalized health programming for nutrition, exercise, and sleep as well as emotional and physical wellbeing. Dr. Bill Baer finds joy beyond the office as he cherishes moments with his wife Sue, their four children, and indulges in the great outdoors and various sporting pursuits.

Dr. Gerry Witherell

Family Medicine physician with over two decades of experience. Born and raised in West Michigan, Dr. Witherell training began at Michigan State University, where he completed his undergraduate studies before completing his medical degree at the Michigan State University College of Human Medicine

In his practice, Dr. Witherell fosters a friendly, comfortable, and collaborative environment, valuing the partnership between physician and patient. He embraces the principles of concierge medicine, recognizing the significance of personalized care tailored to individual needs. Moreover, he remains abreast of cutting-edge innovations and therapeutics, eager to incorporate them into his practice for the benefit of his patients.

Dr. Witherell enjoys DIY home projects, woodworking, playing bad golf, traveling with his family and friends, and rooting on his beloved Spartans!


Brittany Palazzolo

In addition to optimizing patient health daily, Brittany provides extensive dermatology expertise while also overseeing acute care visits.

Jody Koutz

Jody has been practicing as a Registered Dietitian for 20+ years, originally earning her Bachelor's degree in dietetics from Eastern Michigan University and continuing on to complete a Master's degree from Rutgers University. Jody is dedicated to guiding individuals toward healthier lifestyles through personalized nutrition plans. Her evidence-based approach focuses on empowering patients to make informed choices, whether managing chronic conditions, enhancing athletic performance, or adopting balanced eating habits. She works together with our medical team to help patients implement lifestyle choices that complement their concierge medical care.

Jody enjoys traveling with her family, trying new foods all over the world, as well as spending time hiking and outdoors.


Kelly Shomin

Kelly has over 27 years of nursing experience, with a diverse background that includes cardiac, emergency, surgery, and case management nursing.  Kelly holds a Bachelor of Science in Nursing from Valparaiso University.  She enjoys connecting with patients and utilizing her nursing skills to provide compassionate care.

Outside of Kelly's professional life, she loves spending time with her family and friends. Kelly has made yoga and meditation part of her daily practice and finds joy in exploring new places with hiking and traveling to new places.

Kelly's passion for healthcare, combined with her commitment to holistic wellness, drives her to make a positive impact on the lives of others.

Office Manager

April Landis

April, a cornerstone of the concierge medicine clinic since its inception, brings a wealth of experience to her role. With over two decades of dedicated service in healthcare management, she is a seasoned professional adept at navigating the complexities of the field. Hailing from Lowell, April is a true jack of all trades, seamlessly handling a myriad of responsibilities with finesse and dedication. Beyond her professional pursuits, April finds joy in camping and the art of cake making and decorating, indulging her creative spirit in crafting delicious and visually stunning confections.

Mirta Stearns

Mirta is a dedicated Licensed Practical Nurse (LPN) with a passion for providing gentle and precise care to patients. With 19 years of experience in the healthcare field, Mirta has an understanding nature and strong communication skills that enable her to connect with patients and their families, enhancing a supportive and comforting environment.

Mirta is committed to ongoing learning and professional development and staying updated with the latest healthcare practices and technologies. She will always strive to make a positive impact.

Outside of work, Mirta enjoys spending time with family, attending concerts as well as reading a good book or watching a movie.


Alison Rietman

Alison is a compassionate Licensed Practical Nurse (LPN) specializing in outpatient care, dedicated to providing exceptional healthcare services to patients outside the hospital setting. With 7 years of experience, she excels in delivering personalized care and fostering positive patient experiences.

Alison thrives in collaborative environments and works closely with multidisciplinary teams to coordinate patient care effectively. Committed to continuous learning and professional development, she stays updated on the latest advancements in outpatient healthcare practices.

Outside of work, Alison enjoys spending time on her family’s horse farm, sharing her knowledge by teaching lessons and coaching a local equestrian team. In her free time, she enjoys trail riding. Her and her partner, Nate, have two dogs and enjoy spending time playing outside with them.

With a passion for outpatient nursing and a commitment to patient-centered care, Alison is proud to make a positive impact on the health and well-being of individuals in the community at Exponential Health.


LaDon Chantrenne-Hoezee

LaDon is a dedicated Registered Nurse (RN) with over 30 years of expertise in patient-centered care. Her extensive background spans inpatient and outpatient oncology nursing, leadership, and revenue cycle management, reflecting a holistic understanding of healthcare
Committed to addressing every facet of the patient's journey, LaDon excels in anticipating and meeting patient needs with a focus on clinical assessments, advocacy, and care coordination. She possesses meticulous attention to detail and proactive problem-solving
skills, ensuring optimal outcomes for her patients.
LaDon's passion lies in delivering a seamless and personalized healthcare experience. She believes in the importance of quality care while maintaining a mindful connection with her patients. In her leisure time, LaDon cherishes moments with family and friends,
indulges in beach walks, explores new culinary experiences, and remains steadfast in her commitment to personalized, compassionate care.
Operations Director

Mandy Reed

Mandy is a leader at the forefront of healthcare transformation. With over 15 years of healthcare administrative experience, a master’s degree in health administration and experience as an adjunct professor within the School of Public and Nonprofit Health Administration, she has honed her expertise in healthcare operations and innovation.

Mandy’s passion lies in revolutionizing the industry by emphasizing wellness and personalized care. She champions strategic initiatives that prioritize patient-centered approaches, driving high-quality outcomes while reducing costs. By integrating technology and innovation, she paves the way for more sustainable and equitable healthcare delivery.

Throughout her career, Mandy has steered large-scale change and innovation efforts, fostered high-performance teams and cultivated a culture of excellence. Her dedication to transforming healthcare is evident in her commitment to elevating the standard of care delivery, ensuring that every individual receives the attention and support they need to thrive.

Be part of a team that’s changing lives.

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The Castle

Unit 345
2500 Castle Dr
Manhattan, NY


T: +216 (0)40 3629 4753

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