An individual may be invited or may petition to join an active chapter of Pi Gamma Mu when he/she is or was a junior, senior or graduate student in the upper 35 percent of the class, with at least 20 semester hours in social sciences and an average grade therein of "B" or better.  Pi Gamma Mu's constitution defines the social sciences to include the disciplines of history, political science, sociology, anthropology, economics, international relations, criminal justice, social work, psychology, social philosophy, history of education, and human geography.

Faculty and administrators may also accept the privileges and responsibilities of membership in a collegiate chapter.  Membership comes only through established chapters.

The international membership fee is $40.  It includes a handsome certificate suitable for framing, a membership card, a gold-plated key pin, and one-year subscriptions to the Society's journal and newsletter.  Faculty chapter sponsors send membership application forms along with an institutional check to headquarters where memberships are processed.  Chapters may also assess local dues.

Membership in Pi Gamma Mu is a valuable asset and may increase the Civil Service rating at which a person enters federal service.  In addition, other employers look for honor society status on resumes.