Mosbakk was a member of the board of Framfylkingen from 1972 to 1974 and the Norwegian State Housing Bank from 1978 to 1986.
During his tenure, Mosbakk played a role in shaping the direction of Framfylkingen from 1972 to 1974, and later contributed to the development of the Norwegian State Housing Bank's strategies from 1978 to 1986.