In 1900, the ongoing wave of industrialisation led to the foundation of both smaller and larger public health insurance funds across all of Switzerland. This was also the case in canton Graubünden, where the current company that goes by the name of ÖKK has its origins.
Starting after the Second World War, almost 40 independent regional funds worked increasingly closer together, before they joined together in 1994 to form the ÖKK foundation. In 2004, ÖKK Winterthur came on board. Since then, all other city and regional ÖKK funds have assumed another name or no longer exist.
Today's ÖKK is a modern insurance company headquartered in Landquart, which operates throughout Switzerland. ÖKK has grown significantly in Graubünden and has a high market share there. However, ÖKK has also become more prominent outside of Graubünden, as well. Nowadays, around half of its policyholders come from other regions.