Do I need an appointment?
Some German missions in the US require an appointment for citizenship questions and applications whereas some receive your applications as walk-ins during their Business hours. Please check the Website of the Embassy or the Consulate General in charge for the state you live in before coming by: Appointments
If you are not sure which mission is responsible for you, you can find out here: Consulate Finder
I have received dual citizenship by birth and have not acquired any other citizenship voluntarily since my birth. Do I have to choose between the two citizenships at the age of 18?
German law, in general, does not oblige you to choose between the two citizenships at the age of 18.
How can I obtain a certificate proving my German citizenship?
If your citizenship status cannot be determined by the German diplomatic or consular mission and in some other cases where the law requires it, you will need to apply for a German certificate of citizenship (Staatsangehörigkeitsausweis). Such a certificate might be needed in order to be able to issue you a German passport.
Processing times for these applications can be fairly long depending on the amount of necessary research and the possible involvement of other government Offices.
I was born from one or two German citizens but was then adopted by US parents. Am I eligible for “dual citizenship” and a German passport? Do I still possess the German citizenship?
This depends on different aspects, esp. the date of your adoption and if you were adopted by only one US parent as a step-child-adoption or by spouses.
In some cases you might still be a German citizen. If you think you meet the requirements, please inquire with the competent German mission by sending a short letter with simple copies of your birth certificate, adoption decree, certificate of naturalization/citizenship (and other relevant certificates) by regular mail.
Please do not forget to indicate your address, an e-mail-address and a phone number in order to answer your inquiry in the most efficient way.