Greencard as child of a US citizen

[randompseudonym]

I am looking for help. I am the son of a US citizen, who came to Germany at the age of just 6 months and has not been physically present in the US since and has also no intentions to establish a domicile in the US. I am born in Germany and I am 25 years old now. I am desperately looking for a way to get either a Green Card or citizenship, but I cannot find a route whatsoever that leads to citizenship or even immigration. This cannot be right. There must be some way for me to at least be allowed to live and work there.

Am I really not missing anything? Does anyone have an idea that could help me here?

[newacct]

There might have been a way while you were under 18 -- if your US citizen parent had a US citizen parent (i.e. your grandparent) who had been physically present in the US for 5 years cumulatively, your parent could have applied for you to naturalize under the INA 322 naturalization process. But that whole process, including the oath in the US, must have been completed before you turned 18. It is too late now. And without your parent moving back to the US, you can't immigrate through them, so your parent isn't any help to your ability to immigrate to the US.