Social insurances in Germany
Social insurance is usually mandatory for all employees in Germany. Therefore, reserachers who are employed in Germany via an employment contract take part in the full German social security system. Researchers on a fellowship are generally exempt from the obligation to pay contributions to the German social security system. However, they normally have to be insured in a private health insurance scheme.
On the webpage of the research network EURAXESS you find detailed explanations concerning all sorts of insurances in Germany.