UnitedHealth Group

UnitedHealth Group is the largest health insurance provider in the United States, serving more than 29 million Americans, and more than 50 million people worldwide. Since its inception in the 1970s, the company has grown steadily through acquisitions, a strategy that has at times drawn antitrust scrutiny. As of 2025, UnitedHealth Group ranked third on the Fortune 500 list, behind only Walmart (WMT) and Amazon (AMZN).

Business model

UnitedHealth Group is split into two divisions: UnitedHealthcare, which provides insurance plans, and Optum, its noninsurance medical services group. UnitedHealthcare, which accounts for over half of the company’s revenue, is divided into four segments:

• UnitedHealthcare Employer & Individual provides employer-sponsored plans alongside individual and family plans and Affordable Care Act (ACA) marketplace plans.
• UnitedHealthcare Medicare & Retirement offers Medicare Advantage, Medicare Part D, and Medicare Supplement (Medigap) coverage, as well as group retiree service.
• UnitedHealthcare Community & State provides Medicaid, Dual Special Needs (D-SNP), and Children’s Health Insurance Program (CHIP) coverage.
• UnitedHealth Global manages plans in more than 100 countries outside of the United States.

Optum, which was created in 2011, provides medical services outside of insurance. It is divided into three segments:

• Optum Health manages or owns primary and specialty care clinics as well as offering telehealth. It also partners with skilled nursing facilities (SNFs) to offer home and community care.
• Optum Insight provides digital services and analytics to payers, providers, governments, and life sciences companies.
• Optum Rx specializes in pharmaceutical services.

1970s–2000: HMO innovation and early growth

UnitedHealth was founded by Richard Taylor Burke as Charter Med Incorporated in 1974 and restructured as United Healthcare Corporation in 1977. The company initially focused on health maintenance organizations (HMOs), a novel concept at the time, that prioritized preventative care and paid doctors for the number of patients seen rather than services provided. By 1984, the company operated 11 HMOs across 10 states; it purchased HMOs Share Development and Peak Health Care over the next two years. Kennett Simmons, the former president of Peak Health Care, took over the company after Burke resigned after a conflict over coverage with member hospitals.

The company went public in 1984 and began expanding through acquisitions the following decade, beginning with its acquisition of Ramsey-HMO in 1994. Revenue climbed past $11 billion by 1997, reflecting the company’s rapid expansion. The same year, it was chosen as the insurance provider for the American Association of Retired Persons (AARP). The company was restructured again in 1998, with United Healthcare Corp. becoming a subsidiary of UnitedHealth Group.

2000–2010: Aggressive expansion and legal woes

In 2000 the American Medical Association brought a class-action lawsuit alleging that UnitedHealth used faulty data in order to reduce payouts to physicians and plan members. (UnitedHealth settled the lawsuit in 2009 for $350 billion without admitting or denying guilt.)

In 2002 UnitedHealth expanded its Medicaid services by acquiring AmeriChoice for $530 million. The company continued its vigorous acquisition strategy into the early to mid-2000s, acquiring companies including Mid Atlantic Medical (in a $2.7 billion deal), Oxford Health ($4.9 billion), and PacifiCare ($8.1 billion). In 2006 the company was involved in a scandal when then-CEO William McGuire was found to have been backdating stock options as a result of a U.S. Securities and Exchange Commission investigation. McGuire quickly stepped down.

In 2007 the company announced a deal to acquire Nevada-based Sierra Health Services. The Department of Justice sued UnitedHealth Group to stop the merger, fearing the acquisition would reduce Medicare service competition in the state. The deal went through the following year after UnitedHealth agreed to sell its Las Vegas Medicare Advantage program to competitor Humana (HUM).

2010–2020: Entering Optum and exiting the Affordable Care Act

In 2011 UnitedHealth unified its health services under the Optum brand. Alongside the already existing Optum Health, the company’s Ingenix brand was renamed Optum Insight and its Prescription Solutions brand was renamed Optum Rx. The company continued to invest into the health services side of its business when it acquired Catamaran in 2015, which at the time processed the fourth-largest number of prescriptions in the U.S., in a deal valued at just under $13 billion.

In 2016 UnitedHealth Group announced it would be exiting all but a few Affordable Care Act state exchanges, citing hundreds of millions of dollars in losses in 2015 and 2016. However, the company would reenter the marketplace in several states by the early 2020s.

The company continued to build out its health services portfolio with the 2017 acquisition of Surgical Care Associates, which operated around 200 surgery centers. In 2019, it bought DaVita medical group, adding another 280 clinics and 35 urgent care centers to its portfolio.

2020s: Antitrust wins, Medicare controversies, and executive shake-ups

UnitedHealth Group faced significant controversy for its interactions with Medicare Advantage during the early to mid-2020s, with the Department of Justice filing a lawsuit alleging that the company “obtained inflated risk adjustment payments based on untruthful and inaccurate information about the health status of beneficiaries.” Although the case was initially brought forward by a whistleblower in 2011 before being taken over by the Department of Justice in 2017, investigations into the scandal by outlets including The New York Times, The Wall Street Journal, and The Guardian added new layers and fuel to the controversy.

In 2023 the company secured its largest acquisition since Catamaran when it acquired medical payment-processing firm Change Healthcare in a $13 billion deal, despite a challenge from the Department of Justice.

In December 2024, UnitedHealthcare CEO Brian Thompson was shot and killed in New York City. Luigi Mangione was later arrested and charged with the crime. The shooting sparked intense media coverage, with some online communities portraying Mangione as a symbol of resistance against the health insurance industry.

Just days after the shooting, UnitedHealth Group CEO Andrew Witty published an op-ed in the New York Times titled “The Health Care System Is Flawed. Let’s Fix It.” Witty abruptly stepped down in May 2025, citing personal reasons—although the exit closely followed the company reporting an earnings miss for the first time since 2008. Witty was replaced by Stephen Hemsley, the company’s executive chairman, who had previously served as CEO from 2006–2017.

UnitedHealth legacy

Over five decades, UnitedHealth Group has evolved from a regional HMO innovator into a global health care powerhouse. Its dual-engine model—combining insurance with expansive medical services through Optum—has helped reshape how care is delivered and paid for in the U.S. health system. Although its acquisition-driven growth has drawn scrutiny and sparked legal challenges, UnitedHealth’s scale, influence, and profitability have made it a defining force in modern American health care—and a benchmark for the scale and complexity of today’s system.