UnitedHealth Group significantly increased spending on security for top corporate leaders last year with the Dec. 4 killing of health insurance executive Brian Thompson.

The Eden Prairie-based health care giant said it spent more than $1.6 million on security for five top executives last year, including CEO Andrew Witty, according to a regulatory filing Monday.

Thompson, who was CEO of insurance division UnitedHealthcare, is the only named executive for whom there was no security spending, which suggests the expenses for other corporate leaders were incurred after he was fatally ambushed in New York City.

For 2023, by contrast, the company listed no security expense for Witty, Thompson or any of the company's named executives.

"We provide personal and home security services for our executive officers," the company said in its annual filing on executive compensation with the U.S. Securities and Exchange Commission. "We believe that these security services are appropriate and necessary given the risks associated with executive officer positions at the company."

UnitedHealth Group said it would not comment on the spending.

According to the filing, two board members also received company-paid personal and home security services last year.

In addition, UnitedHealth Group listed $207,931 in personal and home security service expenses for certain family members of named executive officers. And the company paid $271,203 to support Thompson's family, including funeral expenses, family transportation and home security costs.

UnitedHealth Group and its UnitedHealthcare unit, which is the nation's largest health insurer, have faced security concerns in the months after the killing of Thompson as he was walking to an investor meeting in New York City.

Earlier this month, an armed man was arrested and charged with making threats of violence after contacting authorities and threatening to shoot a UnitedHealthcare building in Minnetonka while he was parked outside the two-building campus there. Though he apparently did not have specific grievances with the company, the incident prompted a lockdown at the campus.

If UnitedHealth Group provided security for named executives in 2023, it did not hit or exceed the $10,000 threshold set by the SEC for companies to detail spending on perquisites and personal benefits for top leaders.