Can I get German citizenship (again) if I live in Germany again as an American?

Often, for example, citizens who have lived in the U.S. for a long time return to Germany, then receive a residence permit/residency as an American, and wish to be re-naturalized. As a rule, when a former German who only has American citizenship is re-naturalized in Germany, the respective authority requires as a prerequisite that the U.S. passport be surrendered (Renunciation of Citizenship). This can be avoided.

There are two main categories of renaturalization:

a. To become German without retaining U.S. citizenship, which is easier.

b. To become German with retention of American citizenship. This is more difficult, but possible.

The issue here is that former German citizens, without Article 116 of the German Constitution being applicable, acquired
American citizenship in the U.S. at a time when retention was not provided for under German law – before the year 2000.