The uninsured rate in Germany is so low (.2%) that it seems like most of the time that's not even a big deal. But it's generally billed to the patient from what I understand.
Not quite true, it is in some ways similar to the US, with public and private insurance. However the majority is part of the public insurance, and in general health insurance is mandatory. There are some awkward ways by which you can fall out of private insurance and can't get back into public insurance, but these cases are rare.
In case of not having an insurance you'd be billed like any privately insured patient.
See:
* https://en.wikipedia.org/wiki/Healthcare_in_Germany
* http://www.npr.org/templates/story/story.php?storyId=9196396...