In the Fall of 2005, Jeff became an Assistant Professor in the School of Theatre and Film, Herberger College of the Arts at Arizona State University. From 2003-2005, he was Senior Lecturer/Interim Director of the MFA Performance program in the School. From 2001-2003, he was Resident Artist/Senior Lecturer in Theatre at the Institute for Studies in the Arts at ASU.

In Spring 2005, the graduating students from his MFA Performance program presented three original performance art works as part of the ASU Festival of New Works, the first time such work was seen as part of the Mainstage series. In addition to mentoring the MFA Performance students, Jeff teaches Introduction to Movement for Actors, Solo and Collaborative Performance (Theory/History/Practice of Performance Art), MFA Playwrighting workshop (emphasis on solo monologue), Acting Beyond Realism, and Devising for Theatre for Youth. Jeff coordinates a collaborative project with the Mayo Clinic Hospital, employing ASU graduate Theatre students to role-play patients and family members, allowing nurses to practice conversations and palliative care for those facing a life threatening illness.

Jeff has taught and given presentations as a visiting artist at Instituto Superior de Artes (Havana, Cuba), Dartington College (U.K.), Glasgow School of Art, the Center for New Dance Development (Arnhem, the Netherlands), artsadmin (London), Arts University (Brno, Czech Republic), Univ. of Nevada/Las Vegas, Univ. of Southern California, Scripps College, University of LaVerne , Columbia College, (Chicago), Univ. of California, Cleveland State University, State Univ. of NY/Brockport, Martha's Vineyard Public Schools, Los Angeles Poverty Dept. (Theater Group), Otis Art Institute; Fieldston Performing Arts Inst. (NYC), and Barnsdall Art Park (LA). He has held appointments as adjunct professor at Kutztown University, Otis Art Institute, Art Center College of Design, and the California Institute of the Arts. From 1983-2001, he worked as a teaching artist in aesthetic education and creative movement with Hospital Audiences, Inc., Lincoln Center Institute, Young Audiences/NY, Arts Horizons, Orchestra of St. Lukes, Little Meadows Early Childhood Center, ArtsGenesis, and the North Carolina Arts Council. He has published essays regarding his teaching experiences and philosophy in PAJ/Performing Arts Journals #84 (2005) & #50/51 (1995), and Teaching Tolerance (Fall 1996). For the 1996 “Performance Art, Culture, Pedagogy” Symposium at Penn State University, McMahon was a featured performer, and was then cited in the book resulting from that symposium, PERFORMING PEDAGOGY: Toward an Art of Politics by Charles Garoian (SUNY 1999). In 1998, he completed a Master of Fine Arts Degree in the Writing Program at the School of the Arts, Columbia University.
He has chaired panels for the College Art Association and the Assoc. for Theater in Higher Education, and presented at the Modern Language Association, the Rothermere American Institute at Univ. of Oxford, Performance Studies International, Hemispheric Institute for Performance and Politics, Lincoln Center for Applied Ethics, Society for Scientific Study of Sexuality, American Dance Guild, and the New York Foundation for the Arts/Common Ground.