Marsh & McLennan Cos. Inc. was hit by a data breach in April involving access to Social Security numbers and other personal information of staff, former staff, clients and a range of other people linked to the brokerage. Marsh McLennan notified that the breach involved a limited set of data and it reset system access rights and imposed additional restrictions. The information involved included names, Social Security numbers or other federal tax identification numbers. The company offered complimentary credit monitoring for two years, identity theft detection and resolution services and up to $1 million in identity theft insurance coverage.

The California Office of the Attorney General reported a data breach involving Kroll Background Screening Services, a subsidiary of Marsh & McLennan Companies, Inc. The breach occurred between June 2013 and September 2013, resulting in unauthorized access to personal information, including names and Social Security Numbers. The breach notification was reported on November 26, 2013.