Thyme Care has announced a series of leadership changes intended to support the continued growth of its oncology care platform while opening new areas of business focused on some of the most persistent challenges across cancer care.
Brad Diephuis, MD, currently Thyme Care’s president and chief operating officer, has been appointed chief executive officer. He will assume the position on September 1, 2026.
Co-founder Robin Shah will transition from chief executive officer to executive chairman, where he will focus on developing new business lines across drug affordability, clinical trial access, and care alignment. Marcia Macphearson has joined the company as chief operating officer, effective immediately, while co-founder Bobby Green, MD, will continue serving as president and chief medical officer.
A New Leadership Structure for Thyme Care’s Next Chapter
The leadership transition comes as Thyme Care seeks to scale its established oncology care model while pursuing opportunities beyond its core operations.
The company’s platform is currently available to 10.5 million people across all 50 US states and manages approximately $6 billion in oncology spending. Thyme Care works with patients, oncology providers, health plans, employers, and risk-bearing organizations to coordinate care across the cancer journey.
Under the new structure, Diephuis will lead the company’s core business and continued expansion, while Shah will concentrate on launching initiatives addressing broader systemic barriers affecting cancer care.
Thyme Care stated that the changes reflect the strength of the business developed during the company’s first six years and its plans to expand into areas where fragmentation continues to create barriers for patients, providers, and payers.
Brad Diephuis to Lead Continued Growth
Diephuis is a primary care physician with experience spanning clinical medicine, healthcare operations, public policy, and value-based care strategy.
He joined Thyme Care in 2022 and has played a central role in developing the company’s operations and payer expansion strategy. Before joining Thyme Care, he served as a senior advisor at the Center for Medicare and Medicaid Innovation, where he contributed to the development of accountable care and total-cost-of-care programs, including ACO REACH.
Diephuis is also a cancer survivor, an experience that has informed his understanding of the challenges patients face while navigating a complex healthcare system.
“For too long, the responsibility for what happens in cancer care has been spread across so many parties that no one is connecting the dots for the person living through it,” Diephuis said.
He noted that Thyme Care was created to place patients at the center of care and bring greater coordination among the organizations involved in their treatment.
“As CEO, I am committed to making sure that every patient, clinician, and health plan we work with experiences a system that finally moves together, where patients feel supported, providers have a trusted partner, and health plans can rely on a model that delivers sustainable value,” he added.
Clinical Leadership Remains at the Center
Diephuis will lead Thyme Care alongside Green, a medical oncologist who has helped shape the company’s clinical and strategic direction since its founding in 2020.
Green will continue to serve as president and chief medical officer, maintaining responsibility for the company’s clinical approach and its relationships with oncology providers.
“Individuals with cancer deserve a care team that surrounds them at every step,” Green said. “The oncologists treating them anchor every part of that work, and we extend their reach into the moments between visits when patients need support most.”
He credited Diephuis with helping establish the commercial and operational foundations required to deliver Thyme Care’s model on a larger scale.
“Brad has been central to building the commercial and operational foundation that makes this work possible at scale, alongside an incredible, mission-oriented team,” Green stated.
Marcia Macphearson Joins as Chief Operating Officer
Macphearson brings 25 years of healthcare experience to her new role as chief operating officer.
She most recently served as chief commercial officer at Imagine Pediatrics, where she supported the expansion of the organization’s value-based care business. Before that, she spent approximately a decade as a senior partner at Oliver Wyman, advising health plans and provider organizations on enterprise strategy and organizational performance.
Her appointment is effective immediately and forms part of Thyme Care’s broader effort to strengthen its leadership team during a period of commercial growth.
Commercial Momentum and Reported Outcomes
During the first half of 2026, Thyme Care added three health plan partners and expanded existing relationships with national Medicare Advantage and commercial health plans.
The company also released its annual Impact Report alongside the leadership announcement.
According to Thyme Care, its model was associated with a 16% reduction in all-cause inpatient utilization among eligible members of one Medicare Advantage client. The company also reported a 30% reduction in avoidable readmissions among members who completed its readmission prevention program.
For another Medicare Advantage client, Thyme Care reported a 10% decrease in the total cost of care.
These findings form part of the company’s case for expanding a model that combines dedicated care teams, longitudinal patient support, provider collaboration, and financial accountability.
Robin Shah to Build New Oncology Business Lines
As executive chairman, Shah will focus on developing initiatives addressing challenges that often fall between traditional healthcare stakeholders.
The company has identified drug price volatility, clinical trial access, and care alignment as its initial areas of focus.
Thyme Care stated that fragmentation in these areas can increase costs, create unnecessary complexity, and limit access to appropriate care. The company plans to draw on the infrastructure, relationships, and data supporting its existing model to develop additional solutions.
“The next era of oncology won’t be defined by a single breakthrough. It will be defined by how well the ecosystem works together on behalf of patients,” Shah said.
He explained that Thyme Care’s work with patients, providers, and payers has given the company insight into the challenges that continue to divide the cancer care system.
“That vantage point gives us a unique understanding of the challenges that continue to fragment cancer care and an opportunity to build solutions that help the system work better for everyone,” he added.
Aligning Responsibility Across the Cancer Journey
Thyme Care coordinates patients, oncology providers, and health plans through a shared care model designed to improve outcomes and reduce unnecessary costs.
Through dedicated care teams and a purpose-built technology platform, the company supports patients between clinical visits, identifies gaps in care, and integrates its services into existing provider workflows.
Thyme Care also assumes responsibility for both the cost and quality of care. Its model is designed to reduce avoidable emergency department visits, support clinically appropriate treatment decisions, and extend the reach of oncology practices beyond scheduled appointments.
With Diephuis leading the company’s established operations and Shah developing new strategic initiatives, Thyme Care is positioning its leadership team around two parallel objectives: strengthening its current cancer care model and addressing broader challenges affecting access, affordability, and coordination across oncology.
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Written by Nare Hovhannisyan, MD