Dear Colleague,

2025 was a significant milestone for OneOncology as Cencora finalized a definitive agreement to acquire the majority of outstanding equity interests it did not currently own in OneOncology. The transaction closed in February 2026.

Cencora’s decision to accelerate its acquisition of a majority stake in OneOncology validates our mission, vision, culture, and the tremendous value we’ve delivered for our practice partners.

Cencora recognizes the importance of physician leadership, independence, and expanding access to care. They are committed to preserving our servant-leadership culture where OneOncology works with our physician partners to provide the highest quality care at costs that are below what is delivered in the hospital setting. Cencora’s guiding principles for OneOncology’s continued growth preserve our independence — with our own separate board — that will govern key decisions, including new practice affiliations, growth investments to support practices, and resourcing of the MSO.

As Bob Mauch, President and CEO of Cencora said: “As partners to OneOncology since its inception, we have witnessed first-hand the collaborative approach OneOncology takes to drive value to its physician partners and the impact this has had on OneOncology’s growth. We consider it an honor and a responsibility to protect and enhance this physician-centric emphasis to continue to drive value for independent providers.”

Importantly, the transaction enhances our ability to build and operationalize the “MSO of the Future” by bringing significant value to physicians and their patients through growth investment, clinical innovation, shared services, and expanded technology capabilities.

Given the success of OneR, our clinical research site management organization, we plan to make additional investments to extend its impact across our network. Standing up a clinical research unit is extremely difficult — often too difficult for any single practice to do on its own — yet clinical trials are extremely important to patient care. That’s why having a centralized, shared services offering is extremely important to us, our practice partners, and most importantly, their patients.

Beyond clinical research and clinical innovation, OneOncology will continue to enhance centralized shared services from pharmacy and formulary tools to technology and revenue cycle management. Our ability to use our centralized service offering continues to improve efficiencies and reduce costs for our practice partners.

As you will read in these pages, OneOncology’s growth will continue to be driven by new partnerships at both the MSO and practice levels.

From our Cencora partnership to our physician leadership to our unrelenting focus to deliver value to our practice partners, OneOncology’s past has created an amazing foundation for our future.

I hope you enjoy our 2025 annual report and learn about the amazing initiatives our team is building for our practice partners and their patients.

Sincerely,