I believe that as a single parent in the military, all the government requires of you is that you have a "family careplan." This is just like it sounds. You must make arrangements for your son to be taken care of in times when you cannot do it yourself. It is that simple. Of course the military will allow you to have custody of your son. It sounds to me like either someone told you, or you seem to think that you will give up custody when you go to Basic Training or on Deployment. That is not true, and I do not believe that you need a court order giving your mother custody during those times. If you have custody of your son now, you will still have custody of him while you are at Basic, he will just be living with the person you appointed as his guardian. As for after Basic, once you finish AIT, you will be sent to your permanent duty station. Your orders should reflect that you have a dependant and the government will pay for him to re-locate to your location. If your mother has legal custody then he cannot be included on your orders. There are things like powers of attorneys that could possibly be what you need to explore. But since he is a child, you will have to fill out a "family careplan." You need this not only for when you get deployed but also for when you spend a month or two in the field doing training. Deployment is easy, just send him back to your mother (or whomever is guardian), field training is more difficult b/c you must have a friend at your location willing to keep him, or your mother will have to come over to stay with him.