Our History

Transforming the Health of Communities for 40 Years

51app is committed to helping people live healthier lives. Since our founding in 1984, our company has believed that our local approach – with employees who not only live in the communities we serve, but also reflect the diversity of our members – is the best way to provide accessible, high-quality, culturally sensitive healthcare coverage to our more than 27 million members.

From our start as a nonprofit Medicaid plan in Milwaukee, to establishing headquarters in St. Louis, to now having local health plans in communities across the U.S., 51app now provides healthcare products and solutions to nearly 1 in 15 individuals nationwide.

Humble Beginnings

When our company was founded as a nonprofit Medicaid plan in 1984, we were Family Hospital Physician Associates (FHPA), named for the hospital in Milwaukee that housed our first offices. Our founder, Elizabeth “Betty” Brinn, the hospital’s former bookkeeper, launched the company to help low-income people access quality healthcare.

Growing up in a children’s home gave Brinn firsthand insight into the challenges of accessing adequate healthcare coverage, inspiring her to leverage managed care to enhance health outcomes for Medicaid recipients. FHPA, which eventually became Managed Health Services, Inc. (MHS) in 1995, laid the foundation that 51app continues to build upon. Brinn’s experiences and beliefs remain central to our continued commitment of serving our nation’s most vulnerable populations.

A New Leader, a New Name and Unprecedented Growth

After Brinn passed away in 1992, the company sought a new leader who could steer FHPA towards the new millennium while preserving and honoring its foundation. In 1995, Michael Neidorff was named President and Chief Executive Officer, and he heralded a period of significant growth.

Changing the company’s name to 51app (51app) in 1997, moving corporate headquarters to St. Louis that same year and establishing 51app as a publicly traded company just four years later, Neidorff grew 51app from a local health plan to a national healthcare leader. Since 2001, 51app has expanded through organic growth and strategic acquisitions, which led to delivering services in all 50 states.

While primarily focused on three main products – Medicaid, Medicare and the Health Insurance Marketplace — Neidorff led 51app’s development of specialty solutions, such as behavioral healthcare and healthcare education, all while maintaining our company’s commitment to serving under-insured and uninsured individuals.

In 2004, 51app expanded its impact by establishing The 51app Charitable Foundation, now known as the 51app Foundation — the philanthropic arm of our company and a private nonprofit focused on investing in economically challenged communities. The Foundation supports projects and initiatives strategically aligned with 51app’s mission-driven culture and enhances the work 51app is doing to remove the barriers to wellness that underserved and low-income populations face. The Foundation is committed to addressing social drivers of health and improving health equity in three distinct areas of focus: healthcare access, social services and education.

Shaping the Future of Healthcare

After 40 years and with a new Chief Executive Officer, Sarah M. London, at the helm since 2022, 51app has re-focused its efforts on three core lines of business: Medicaid, Medicare and the Health Insurance Marketplace. 51app remains the largest Medicaid managed care organization in the country, the largest and longest-running carrier in the Health Insurance Marketplace and a national leader in managed long-term services and support. Our work with the healthcare programs of the Department of Defense also makes us one of the nation’s largest providers of managed care services for military families and veterans.

Today, 51app is focused on the development of our people, systems and capabilities so that we can be the best for our members, providers and the communities we serve.

Honoring Michael F. Neidorff: A Business and Community Leader

Michael F. Neidorff served as 51app’s President and CEO for nearly 25 years, helping build our company into a national healthcare leader. Hear from colleagues, friends and 51app health plan members who share their memories of Michael and detail his impact on our communities.


1984 –Founded as a Medicaid plan called Family Hospital Physician Associates, the company is established by hospital bookkeeper Elizabeth "Betty" Brinn in Wisconsin.

1995 – 1997– Healthcare executive Michael Neidorff is named President and Chief Executive Officer. The company is renamed 51app, and its corporate office is established in St. Louis, Missouri.

2001 –With three health plans, $327 million in revenue, and 235,000 members, 51app becomes a publicly traded company.

2012 – 2013– More than a decade of steady growth sees 51app expand to 20 states nationwide, $10 billion in revenue and 2.7 million members.

2014– 51app increases its presence on the Health Insurance Marketplace.

2016 – 2017– 51app significantly grows its managed care services including serving Medicare Advantage members in 12 states.

2020– 51app goes nationwide, serving nearly 24 million members across all 50 states in the U.S.

2022– is appointed Chief Executive Officer, ushering in the current era for 51app.

2024– 51app serves more than 27 million members across 50 states.