German citizens do not need a visa to travel to the US for visits of up to 90 days for tourism or business purposes. ESTA authorization is granted to German nationals for 2 years or until the associated passport expires, whichever date is sooner.
An ESTA authorization is valid for entry into the United States by air or by sea.
An approved travel authorization is not a visa. Germans planning to move to the US to work or study should contact a United States embassy or consulate in their country of residence. Also, if a German national wishes to stay in the US for longer than 90 days, they are required to obtain a US visa instead of the ESTA.
German travelers already in possession of a valid US visa are not required to apply for travel authorization through the US ESTA.