MSIG USA is the US-based subsidiary of MS&AD Insurance Group Holdings, Inc., a Japanese insurance group with roots that trace back to 17th-century trading houses. Headquartered in New York, the company underwrites commercial property, casualty, marine, financial lines, and specialty coverage for US-based and multinational businesses. It operates through several underwriting subsidiaries and holds admitted licenses in all 50 states, the District of Columbia, and Puerto Rico.
Website: msigusa.com
Head office address: 1251 Avenue of the Americas, 46th Floor, New York, NY 10020
Founded: roots trace to 17th-century Japan; underwriting marine insurance in the US since 1957
Company type: subsidiary of a publicly traded parent (Tokyo Stock Exchange)
Parent: MS&AD Insurance Group Holdings, Inc.
Regions served: United States (all 50 states, the District of Columbia, and Puerto Rico), with access to a global network across 40+ countries and regions
The carrier’s roots trace to Mitsui and Sumitomo, two Japanese trading houses founded in the 17th century that later built fire and marine insurance businesses. That heritage carried into the US market, where predecessor companies began writing marine coverage in 1957, a line the carrier still underwrites today.
The carrier expanded its balance sheet, added a new regulated entity, and built out its board, with growth concentrated in specialty and cross-border lines rather than standard commercial coverage.
The carrier writes commercial insurance for US-based and multinational businesses across several major lines. Its core offerings include:
MSIG USA also underwrites excess and surplus lines through MSIG Specialty Insurance America, Inc., its newer platform for risks that fall outside the standard market. Between its admitted and E&S platforms, the carrier covers a wide swath of the commercial risk spectrum.
As part of MS&AD Insurance Group Holdings, the carrier draws on a network that spans more than 40 countries and regions, along with affiliated specialty providers such as MSI Guaranteed Weather and MS Amlin. That reach lets the insurer place risk across more territories than a standalone US carrier typically can.
MSIG USA’s growth in gross written premium and its move into excess and surplus lines point to a broader strategy of building out specialty capabilities in areas such as surety, environmental, and healthcare risk, while adding governance depth to match. Its risk engineering division also works alongside underwriting teams to help clients assess exposures, analyze losses, and reduce claims before they occur.
The company says its principles shape both its underwriting approach and its workplace. It describes its core values as:
MSIG USA says it is guided by its parent company’s mission to bring security and safety through global insurance and financial services, along with a stated vision of sustainable growth.
