marines officers who are under contract in the service taxes and fees ? ?

So I’m doing a comic book and a character I have is in the marines and I was having a since in the book about her fees.    Quick question Do marines who are officers and under contract pay for a lot of fees, and taxes before they return home ? And if so how much can those things get to that is related to many officers ? This character is a captain she , is having a hard time with her fees and taxes before her contract ends . Can this actually happen and how you think they be owning?