From Academy Bylaws:
Article III, Section 1. Membership shall be by invitation of the Board of Governors. Invitations to active membership shall be limited to those persons active in the motion picture arts and sciences, or credited with screen achievements, or who have otherwise achieved distinction in the motion picture arts and sciences and who, in the opinion of the Board, are qualified for membership.
To be considered for invitation to Academy membership as a Member-at-Large, an individual must:
(a) have been actively engaged for the past 8 years in the production of theatrical motion pictures in a key creative position for which the Academy has no branch,
(b) Sitting executive directors (or holders of equivalent titles) of the DGA, SAG, PGA, WGA and IATSE will automatically be considered for Members-at-Large status by the Board of Governors upon assuming their duties. (The eight-year requirement will be waived for these individuals.) At such time as a successor takes over the position, his or her predecessor will be moved to Associate status,
(c) have been in his or her field for 2 years and have achieved such special distinction, or made so outstanding a contribution to the art or science of motion pictures, that it is the unanimous judgment of the General Membership Committee that membership should be extended.
The General Membership Committee shall evaluate each proposed member on his or her standing, and/or contribution to the motion picture industry.
Proposals must be accompanied by a letter from each sponsor which addresses, as specifically as possible, how the candidate meets one or another of the requirements above.
NOTE: Please refer to special requirements for Creative Science and Technology, Production and Stunt Coordinators.