Thyme Care, a Nashville-based cancer-care startup valued above $1 billion, is changing chief executives. Co-founder Robin Shah is stepping out of the CEO role, and Dr. Brad Diephuis—currently the company's president and chief operating officer—will take over as CEO on September 1, 2026, according to the company's July 15 leadership announcement.
Shah is not leaving. He moves to Executive Chairman to build new business lines, while Diephuis runs the core company. This is a planned succession, not a forced exit.
Table of Contents
- What actually changed at the top
- Why founders step back into a chairman role
- Who is the new CEO
- What Thyme Care does and how to access it
- The money behind the company
- Frequently Asked Questions
What actually changed at the top
The change is a role swap among people already inside the company, not an outside rescue. Diephuis, who has served as COO and president, becomes CEO effective September 1, 2026. Shah, who founded Thyme Care in 2020 and led it as CEO, becomes Executive Chairman. The transition also promotes new operating talent.
Marcia Macphearson joins as COO, bringing 25 years in healthcare from roles at Imagine Pediatrics and consultancy Oliver Wyman, per a citybiz report. That fills the operating seat Diephuis leaves behind. In short, the leadership bench got deeper rather than thinner. One insider moves up, the founder moves sideways into a growth role, and a new operator takes the day-to-day reins.
Why founders step back into a chairman role
Founders often frame a CEO handoff as scaling, and that is how Thyme Care describes this one. As Executive Chairman, Shah will launch new ventures in drug affordability, clinical-trial access, and care alignment, according to HIT Consultant. Those are separate bets from the core navigation business.
This matters because "founder steps down" headlines can signal trouble—a board pushing out a struggling leader, or a distressed sale. Forbes characterized this move as a leadership evolution and a co-founder step-up, not a distressed exit, in its InnovationRx coverage. For readers tracking startup transitions, the tell is where the founder lands and whether operations already have a proven leader. Here, both boxes are checked.
Who is the new CEO
Diephuis is a primary-care physician and a cancer survivor, which gives him both clinical and patient perspective on Thyme Care's mission. Before the company, he was a senior advisor at CMS's Center for Medicare and Medicaid innovation (CMMI), the federal group that tests new payment models. At CMMI he helped design value-based programs, including ACO REACH, per HIT Consultant.
"Value-based" means providers are paid for patient outcomes rather than volume of visits or tests. That background maps directly onto Thyme Care's business model. His insider tenure as COO and president also lowers transition risk. He already knows the operations, the payers, and the roadmap he is inheriting.
What Thyme Care does and how to access it
Thyme Care runs a value-based oncology platform offering 24/7 virtual cancer-care navigation—help coordinating appointments, symptoms, and treatment questions between visits. Forbes reports the company was founded in 2020 and is based in Nashville.
Here is the key limitation for patients and caregivers: you generally cannot sign up directly. Thyme Care sells to health plans and oncology practices, so access reaches patients through their insurer or cancer center, as MobiHealthNews explains. If you want to reach the service, try these steps:.
- Ask your oncology practice whether it partners with Thyme Care for navigation.
- Check your health plan's care-management or oncology-support benefits.
- Confirm cost and eligibility through the insurer or practice, not through a direct consumer sign-up.
The money behind the company
Funding context explains why this transition happens from a position of strength, not desperation. Thyme Care crossed a $1 billion valuation after a $97 million Series D backed by oncology-ecosystem investors, per a PR Newswire release.
Earlier, a $95 million Series C—$55 million equity plus $40 million debt—pushed total funding past $178 million, with investors including CVS Health Ventures and a16z Bio+Health. That investor list signals strategic buyers, not just financial ones, which often shapes a company's willingness to launch adjacent business lines.
Frequently Asked Questions
Is Robin Shah leaving Thyme Care?
No. He is moving from CEO to Executive Chairman to build new business lines in drug affordability, clinical-trial access, and care alignment.
When does the new CEO start?
Dr. Brad Diephuis becomes CEO on September 1, 2026, after serving as the company's president and chief operating officer.
Can I sign up for Thyme Care as a patient?
Not directly. Access comes through your health insurer or oncology practice, since Thyme Care partners with plans and providers rather than individuals.