Superior Underwriters and GSU Insurance Services are divisions of Groninger & Co., Inc. Established in 1928, we operate as a locally-owned independent General Agency with our home office located in Bellevue, Washington. We specialize in hard-to-place, specialty, and surplus lines business and market our products to Independent Agents throughout the United States including; Alaska, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming. We offer various programs for admitted and non-admitted business, and have binding authority to write the following lines: Commercial Property & Casualty, Garage Liability, Personal Lines, and Transportation including business, public, local, intermediate, and long-haul trucking. With over 100 years of collective underwriting experience, our staff works closely with our carriers to provide well-designed products and coverages for our retail partners.