Unfortunately, you cannot be insured under the public health insurance system. However, you can still opt for private health insurance. In case your health insurance is also one of the prerequisites for getting a visa we highly recommend you getting a reliable health insurance provider to avoid the risk of visa rejection.
Our partner, DR-WALTER, has a record of working with foreign guests in Germany, offering coverage that will be perfectly acceptable for your visa application as well as highly usable during your stay in Germany. Contact us to order it right now or to ask for more information.
If you move to Germany with private coverage and find employment later, you can always cancel the private health insurance and then switch to the public.