Marxer was born on 4 November 1960 in St. Gallen as the son of bricklayer Cirill Marxer and his mother Monika Heeb as one of two children.
He attended secondary school in Eschen before attending business school from 1981 to 1984 in St. Gallen and then graduating in business administration in Zürich 1988.
From 1984 to 1994 he worked at the VP Bank in Vaduz, where he was also the deputy director of the bank's branch at the British Virgin Islands.
During this time, he was also a member of the audit, finance and state committee.
[1] Marxer, among other things, has advocated for the increasing of employer pension contributions.