re: 16yo Son wants to be a medic in army or marines

So if he joins he will get at least an EMT cert. Possibly and EMTA. Also if he is in LA and in the national guard, we now get tuition and Fee Exemption, of he wants to go on to be a paramedic.

The army offers a paramedic program but it's mostly reserved for flight medics.

You're correct with the state licensing, but in most states they accept NREMT, a few don't (Texas has its own state process).