天美麻豆

The general requirement is that it should be valid. Would one really expect differently? But in Germany they never expire, so if one has a no longer valid license it is usually because of too many driving violations. You should ask at the B眉rgeramt.  Normally one can drive on a valid foreign license for up to a year and then one HAS to get a German one if having residency. If done within 3 years of getting residency, one can exchange an American license for a German one depending on the State. Some have no exchange, others have partial where one say only has to take either the practical or the written test, others have a full exchange where it is just a matter of paper work and no exams or lessons needed. If one has to do the whole thing, one is required to take lessons and the exams and this cost a few thousand euros. Thus having let the American license expire could be very costly if they don’t accept it!  Best to find out as soon as possible because they might make an exception in such a case but put a strict time limit on it.

I know Americans that have failed to get a German license for some years. They didn’t own a car but occasionally rented and said they never had a problem. But if an accident happened they would be in serious trouble as would the rental place for not properly checking.
Another possibility might be to see if your expired license in the States can be extended or renewed. I did this decades from overseas ago but always before the expiration date. Most States are picky about this but it might be worth inquiring about.

These are the kinds of things in Germany that nobody tells you about, one is expected to inquire and get informed on their own. But I have written on this subject previously on this site:
/forum/viewtopic.php?id=469551


Here is also a link to the US embassy page about this subject:

You can only convert a VALID driving license, of course!

For an American I would add that since it is so much cheaper to get a license in the States, finding a way to get re-licensed there if at all possible, say on a visit, could save a lot of trouble and money depending on the States exchange agreement with Germany. But since the poster appears to be Indian, I assume they no longer have even a second residence or permanent ties to the States?