The Adjutant General is authorized to negotiate and enter into contracts on behalf of all civilian employees of the Army National Guard and Air National Guard under his jurisdiction for membership in an employee retirement, disability or death benefits system, and membership in a group health insurance program, and to enter into agreements with the Secretary of Defense of the United States of America for withholding sums from the compensation of such civilian employees for contributions to such system or program. The Adjutant General is also authorized to designate who shall receive the sums withheld for contributions to the system or program authorized by this Section.