((a)) A person with no prior military service who is qualified under and applicable regulations for enlistment in a regular component of an armed force, or who is qualified under and applicable regulations for enlistment in the Space Force, may (except as provided in subsection (c)) be enlisted as a Reserve for service in the Army Reserve, Navy Reserve, Air Force Reserve, Marine Corps Reserve, or Coast Guard Reserve, or be enlisted as a member of the Space Force, for a term of not less than six years nor more than eight years.
((b))
((1)) Unless sooner ordered to active duty under chapter 39 of this title or another provision of law, a person enlisted under subsection (a) shall, within 365 days after such enlistment, be discharged from the reserve component in which enlisted and immediately be enlisted in the regular component of an armed force.
((2)) The Secretary concerned may extend the 365-day period described in paragraph (1) for any person for up to an additional 365 days if the Secretary determines that it is in the best interests of the armed force of which that person is a member to do so.
((3))
((A)) The Secretary concerned may extend by up to an additional 365 days the period of extension under paragraph (2) for a person who enlisted before , under if the Secretary determines that the period of extension under this paragraph is required for the performance of adequate background and security reviews of that person.
((B)) A person whose period of extension under paragraph (2) is extended under this paragraph shall undergo all security and suitability screening requirements and receive a favorable military security suitability determination before entering into service in a regular or reserve component. Screening priority shall be given to those persons who were enlisted for a military occupational specialty that requires specialized language or medical skills that are vital to the national interest.
((C)) The authority to make an extension under this paragraph shall expire one year after the date of the enactment of the National Defense Authorization Act for Fiscal Year 2018. The expiration of such authority shall not effect the validity of any extension made in accordance with this paragraph on or before that date.
((4)) During the period beginning on the date on which the person enlists under subsection (a) and ending on the date on which the person is enlisted in a regular component under this subsection, the person shall be in the Ready Reserve of the armed force concerned.
((c)) A person who is under orders to report for induction into an armed force under the Military Selective Service Act ( et seq.), except as provided in clause (ii) or (iii) of section 6(c)(2)(A) of that Act (), may not be enlisted under subsection (a).
((d)) This section shall be carried out under regulations to be prescribed by the Secretary of Defense or the Secretary of Homeland Security with respect to the Coast Guard when it is not operating as a service in the Navy.