Veterans

So, yeah he can still use it.

But it is weird that he got retirement and medical after only 17 years. They use to have an early out program where you could get partial retirement pay and medical benefits if you retired early. Called TERA it ended in 2018. As long as he made it past 15 years he was eligible. But someone way up the chain of command would have had to offer and approve it because that program is really designed to shape the force - like getting too many people in one specialty out of the service. Maybe he had a General on his side.

He could have also done 3 years inactive service in the reserve, guard or prior enlisted that counted towards his 20.