How long do you have to live in a state to join the army?

Answer 1

Generally speaking you're a resident the moment you take up residence in that state. That being said, there'll be a minimum amount of time you must have been a resident in order to be eligible for certain programmes. Also, for these programmes, the date you're eligible depends on when you establish verifiable legal residence... that means getting a drivers licence, being employed by an employer in that state, filing taxes with that state, signing a lease for an apartment, receiving utility bills in your name at an address, etc.

I'm afraid the question is much too broad to be answered without knowing what you're trying to do, exactly. Even if those details were probably available, there's a good chance that what you'd need would require qualified legal counsel.

Answer 2

It doesn't matter what state you live in, or how long you've lived in that state. If you're a US citizen, you can enlist immediately after moving to a new state, if you so wish. Foreign nationals seeking to enlist in the US Military must have first established permanent residence in the US - meaning, any state or territory of the US, with no limitations imposed as to how long they've lived in a specific state, so long as their permanent residence within the US is established.