If you are not "drafted" you sign up at a recruiting office, where they are supposed to check you out to see if you are fit for military duty. Originally Posted by i'va biggenActually a "recruiting office" is only the first step. You have to go to an AFEES station to take a physical and a mental evaluation. You sign some paperwork at the recruiting office but the main contract takes place at the AFEES station when you enlist. That is usually where you give your oath to not run away, to not endanger your fellow soldiers, to not give yourself to the enemy, and to not get your fellow soldiers killed.
I will point out that sometimes exceptions can be made if you have a parent in the hospital, the oath can be administered there, or if you want to take it at the Liberty Memorial, then arrangements can be made but these are exceptions to the rule. I took my oath on Pearl Harbor Day.