Seitz, Bishop and Marsh McLennan Agency

Built by Trust,
Strengthened by Experience

Seitz Insurance Agency was founded in April 1961 to serve the rural communities of Eastern Montana. What began as a local agency grew into a comprehensive independent firm offering personal, commercial, life, multi-peril crop, and group health insurance. The agency serves a diverse client base throughout Montana and North Dakota, including clients in the agriculture, construction, energy, municipal, and tribal sectors.

In 2023, the agency expanded its presence into Northwestern Montana with the acquisition of its MIM partner, Bishop Insurance Service. Bishop Insurance has served as a trusted risk-management partner in Northwestern Montana since 1959, earning the confidence of generations of businesses and families through its integrity and personalized service.

In April 2026, Seitz Insurance and Bishop Insurance joined Marsh McLennan Agency. Together, as one unified team, we offer something even greater: a client experience strengthened by shared purpose and amplified resources and a continued commitment to our colleagues and communities. With a broader reach, deeper expertise, and unwavering values, our clients can expect an elevated standard of service.

While the agency has evolved over the years, it remains grounded in its founding values: providing quality service to clients, being a trusted partner to the companies it represents, and supporting the sustainability and well-being of its colleagues and communities.