Upon a determination by the Secretary concerned that a member of the armed forces not covered by section
1201,
1202, or
1203 of this title is unfit to perform the duties of his office, grade, rank, or rating because of physical disability, the member may be separated from his armed force, with severance pay computed under section
1212 of this title, if the Secretary also determines that—
However, if the member is eligible for transfer to the inactive status list under section
1209 of this title, and so elects, he shall be transferred to that list instead of being separated.