Social security ("Sozialversicherung")

Social insurance is mandatory for all employees in Germany. Therefore, if you are employed in Germany via an employment contract, you 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, if you are financing your stay in Germany yourself or  receiving a fellowship, you also have to be insured in a health insurance scheme.
Please refer to the sections below for detailed explanations.

Source and further information: Euraxess

Stay based on a fellowship or financing with own funds