After completing his studies and receiving his doctorate, Christian Moser obtained his post-doctoral lecture qualification in 1887 and subsequently became a private lecturer for mathematics. In 1891, he was appointed by the federal administration as the first federal actuarial mathematician – a position created on the initiative of statistician Johann Jakob Kummer. Moser also taught at the University of Bern, where he was appointed associate professor in 1901 and was the co-founder of the institute on actuarial mathematics in 1902. At the same time, he became the most important expert in the federal administration for preparing the health and accident insurance bill that was rejected by referendum in 1900 and later accepted in revised form in 1912. He represented the social state conceptions and projects of the Confederation at international congresses. In 1905, he became the founding member of the Association of Swiss Actuarial Mathematicians. Encompassing social insurance experts as well as representatives of the private insurance industry, the Association was a major platform for exchange between private and public actuarial mathematicians. In 1904, Moser took over the post of director of the Federal Private Insurance Office from his mentor Johann Jakob Kummer. In 1915, he was appointed full professor for mathematical and technical insurance science at the University of Bern, a position for which he left the civil service. He worked in this professorship and managed the institute for actuarial mathematics until his retirement in 1931. Moser founded the most influential actuarial mathematics school in Switzerland at the time, at least from a social state perspective. Many leading actuarial mathematicians employed by the state or the Swiss Institute for Accident Insurance (Suva), including the future director of Suva, Arnold Bohren, were taught under Moser’s professorship.