NAS Bylaws：
5. Resignations from membership shall be addressed to the home secretary, who will report them to the Council. Not earlier than four years after a member's resignation the Council, by a two-thirds vote, may provide for reinstatement to membership.
Charter and Bylaws, December 2006
BYLAWS OF THE INSTITUTE OF MEDICINE (IOM)：
3. Members who are no longer able or interested in continuing their participation in the Institute's activities may voluntarily request emeritus status at any time. The request must be made in writing to the Home Secretary of the Institute. Emeritus status shall be permanent.
Emeritus members may attend annual and regional meetings of the Institute, but they shall not cast a vote in the Institute's affairs, nor shall they be subject to any dues or assessments. Members who request emeritus status shall not be eligible for appointment to the presidency of the Institute, nor shall they be eligible for election to the Council or appointment to the Membership Committee.
