Generally, as a student in Germany, you will have a few health insurance options to choose from.
Comprehensive private insurance - this is rarely going to be an option since you have to be earning a minimum of €30000/yearly (or €45000 if you are over 50 years of age) to be eligible
Here's the thing. If you can sign up for the public system, you should. In 99% of cases, it's the best thing to do. Students of an accredited German university, under 30 years of age are mandatorily insured in public health insurance, therefore they need to go for it. However, there is an option to exempt yourself from public health insurance at the start of your studies, and choose one of the two other options. As mentioned, we 100% recommend going for public health insurance since you can enjoy the discounted student contribution of around €145/month (earnings from minijobs and working-student contracts do not impact the premium, regardless of the size) while still having the broad coverage of the public health system.
Here are a few reasons why you would not be eligible for public student insurance:
You are over 30 years old: students over 30 years of age are not eligible for student public health insurance
You are studying at a non-state-accredited university: only students in a state-accredited universities are eligible for student public health insurance
You got exempted from public insurance at the start of your studies and went for private or Incoming insurance: if you exempted yourself at the start of your studies, the return to student public health insurance is not possible anymore. You will have to wait until you get a job offer from a German-based company in order to become eligible.
If one of these is your case, or you simply do not want to go for public health insurance, you still have the other two options mentioned above. You will have to exempt yourself from public health insurance in order to enrol into the uni in this case.
It is important to mention that students from the EU/EEA, the UK or Switzerland should remain on their home insurance, and do not need to signup for health insurance in Germany. This is a big benefit because you can avoid paying the contribution in Germany and still enjoy the coverage through your EHIC/GHIC. You can learn more about the topic in our article on EU students.
For more information on this topic, check out this blog post.