UnitedHealthcare CEO Brian Thompson, 50, was fatally shot Wednesday morning in Midtown Manhattan prior to company shareholder meeting. Here are answers to some frequently asked questions about Thompson and UnitedHealthcare.

What is UnitedHealth Group?

Minnetonka-based UnitedHealth Group (UNH) is a diversified traded health care company with more than 400,000 employees. It owns UnitedHealthcare, the nation's largest health insurer. UNH most recently ranked in the top five on the Fortune 500 list of American businesses, just behind Apple, and publicly trades on the New York Stock Exchange. The company is Minnesota's 10th-largest employer, with approximately 19,000 workers in the state.

How is UNH different from UnitedHealthcare?

A division of UNH, UnitedHealthcare (UHC) is the largest provider of health insurance products in the United States. It provides private health insurance for more than 52 million people, including 29 million with private individual or workplace health plans, and more than 20 million people with government-subsidized Medicare and Medicaid plans.

Who was Brian Thompson?

Thompson was appointed chief executive officer of UnitedHealthcare in April 2021 after initially joining UNH in 2004 and serving in a variety of corporate leadership roles. He ran UnitedHealthcare's Medicare business for several years. The University of Iowa graduate had previously worked as a CPA with PricewaterhouseCoopers, according to his company biography. He lived in Maple Grove. Thompson was fatally shot Dec. 4 outside a hotel in New York City before a scheduled annual conference of investors.

What are UNH's other businesses?

Optum is another well-known division of UNH, providing direct health care and pharmacy services along with data analytics of health care trends. Roughly 90,000 physicians are employed by or affiliated with Optum, the largest such tally in the United States. Roughly 40,000 advanced practice caregivers also are employed by Optum or affiliated with the division.

Why is UNH controversial?

The company's insurance division has faced scrutiny in the press and from elected officials for the way it reviews and denies requests or claims for medical care. UnitedHealthcare has been investigated for its use of prior authorization to determine whether services are medically necessary for seniors covered by Medicare Advantage plans.

The U.S. Senate Permanent Subcommittee on Investigations announced in October that UnitedHealthcare, alongside the two other largest Medicare Advantage insurers, Humana and CVS, boosted profits by denying seniors stays in post-acute care facilities while they recovered from injuries and illnesses. UnitedHealthcare's prior authorization denial rate for post-acute care ballooned from 10.9% in 2020 to 22.7% in 2022, according to the subcommittee's report. The denials, the subcommittee wrote in its report, "can force seniors to make difficult choices about their health and finances in the vulnerable days after exiting a hospital."

Was UNH hurt by the Change cyberattack?

A cyberattack earlier this year on another UNH subsidiary, Change Healthcare, affected 100 million patients, making it one of the largest data breaches in U.S. history. Optum acquired Change for $13 billion in 2022. The division processed about 15 billion health care transactions per year before the attack. Some health care providers reported months-long delays in payments of claims in the aftermath of the cyberattack.

Has UNH been the subject of public protests?

Demonstrations outside UNH headquarters in Minnetonka have become larger and generated more attention. Eleven people reportedly were arrested on July 15 when the People's Action Institute staged a protest over the company's refusals to authorize or pay for care. A former Republican state representative, Jenn Coffey, led the protest after exhausting financial resources to pay for cancer care and fighting with UnitedHealthcare over its denials and coverage limitations.

Has UNH been the subject of investigations or lawsuits?

The U.S. Department of Justice launched an antitrust investigation into UNH this year, the Wall Street Journal reported in February, citing unnamed sources. In a statement in July after UNH abandoned two acquisitions, Assistant Attorney General Jonathan Kanter said the proposed deals "raised questions about quality of care, cost of care and working conditions for doctors, nurses and other healthcare providers."