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For them to separate him, with that amount of service, he'd be entitled to a board hearing. So, he will be able to present his history of military service, the fact that he is within 6 weeks of making 20 years, etc. to that board. The board can then consider retention as an option, based solely on his military career. So, that is something he'll want to discuss with his attorney, as he is moving forward. He'll be assigned an attorney if they are planning on doing a board (which they have to do given his tenure).
He can also submit a request for the command to set aside the board in lieu of retirement. He'd need to then be prepared to submit an immediate request for a 20 year letter and retirement packet.
Now, even if the board happens and the board chooses separation, due to his lengthy service, his separation will automatically be reviewed at the highest level (Secretary level review), where they have the ability to separate him with retirement instead of the Chapter 18 (dual processing).
So, those three things together give him the protections to his retirement that are available in the law.
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