Originally Posted by
soitgoes
There's one additional exception that agl120854 referred to. If your license is issued in accordance with the Convention on Road Traffic of 8 November 1968. The US is a signatory to that convention, and some US states issue licenses that comply with the information/numbering scheme defined in that conventions.
However, nonetheless, I agree with your general advice--getting an International Driving Permit is a good idea.
At least from the language agl120854 posted there is not exception. You require a translation if your license was not issued by a member state (true for every US license), OR you require a translation if your license is an a language other then German OR you require a translation of your license does not comply with the Convention.
I certainly did not review the original language, however, the language he posted contains logical ORs and NOTs and describes the instances you require a translation, not the execption