[9][15] Union Mutual, now renamed Unum, began trading on the New York Stock Exchange in November 1986.

[9] Under the leadership of then-CEO James Orr, the company turned its focus to long-term group disability insurance.

[9] In March 1990, Unum acquired National Employers Life Assurance Holdings, which at the time was the United Kingdom's largest disability insurer.

The company originally specialized in providing both medical-aid and accident insurance to employees in high-risk industries, including miners and coal workers.

[22] Chandler initiated a company-wide restructuring at Provident, which included the 1995 sale of its health-related business to Healthsource for $231 million.

[13] When the merger was completed in 1999, the new company, named UnumProvident, was the United States' largest disability insurance provider.

[29] Unum stated that "only 2% of the policyholders who filed a claim with the company last year [2001] were found not to be disabled, an amount consistent with prior experience.

"[34] The review was completed in 2008, and resulted in a 41.7% reversal, "in whole or part", and an additional $676.2 million of benefits paid nationwide by Unum.

[35] The state of Maine press release announcing the result, praised regulators for their work, and the company for coming into compliance.

[35] The company was involved with the UK's controversial Welfare Reform Bill in 2007 and was investigated by the BBC in England at that time.

[39] In 2012 and 2013, Unum partnered with the Consumer Federation of America to release reports which examined the use of disability insurance by American workers.

[40][41] According to numbers released by the Bureau of Labor Statistics that were cited by the report, two-thirds of American workers do not carry disability insurance policies.

[42] In addition, the report found that, among other things, workers know little about disability insurance, despite expecting financial hardship if they were to become unable to work.

[40][41] In 2008 Unum opened its IT centre of excellence in Carlow, Republic of Ireland,[43] and continued to digitize its finance operations,[44] and to invest in technology, in the U.S.[45] and abroad[46] during the following decades.

[1] In 2023, subsidiary Colonial Life & Accident Insurance Company launched Gathr, a proprietary HR tech and benefits administration platform for small businesses.

[50] Unum Group is headquartered in Chattanooga, Tennessee,[4] and maintains offices in Portland, Maine; Columbia, South Carolina; Baton Rouge, Louisiana; Atlanta, Georgia; Milton Court, Dorking, Surrey, Basingstoke and Hampshire, England, Warsaw, Poland and Carlow, County Carlow, Ireland.

[6][51] During the 2010s, Unum collaborated with Oxford Economics, among others, to analyze staff engagement and retention, subsequently designing policies and adding benefits to nurture company loyalty.

[56][57] The company is a long-time participant of the Maine Heart Walk, with COO Mike Simonds serving as the event’s chairman in 2021.