Emeritus Professor of Public Health, Weill Medical College of Cornell University, 2007  

Adjunct Professor of Medicine, Faculty of Medicine, McGill University, 2006 to present 

Adjunct Clinical Professor of Humanities in Medicine, Baylor University, 2018-2013         

Clinical Professor in Public Health, Cornell University Medical College, 1971-2007.

The Master's Class in Palliative Medicine, Royal Adelaide Hospital, Adelaide, Australia, December 1-2, 2000

The Master's Class in Clinical Medicine. University of Virginia School of Medicine, Charlottesville, Virginia, May 11-13, 2000

The Master's Class in Clinical Medicine. March 21-26, 1993, Nashville, Tennessee.

Director, The Cornell Program for the Study of Ethics and Values in Medicine, Cornell University Medical College, 1981-1986.

Lecturer, Mount Sinai School of Medicine, 1971-1973.

Lecturer, Hunter College School of Social Work, 1967-1974.

Associate Clinical Professor in Community Medicine, Mount Sinai School of Medicine, 1968-1971.

Associate Professor in Medicine, Mount Sinai School of Medicine, 1967-1971.

Associate Professor in Community Medicine, Mount Sinai School of Medicine, 1967-1968.

Consultant, Department of Preventive Medicine, University of Washington School of Medicine, Seattle, Washington, 1966-1968.

Associate Clinical Professor in Medicine, Mount Sinai School of Medicine, July-December l966.

Associate Clinical Professor in Community Medicine, Mount Sinai School of Medicine, July-December 1966.

Consultant, Department of Public Health, Cornell University Medical College, 1965-1966.

Associate Professor of Clinical Medicine, New York University School of Medicine, 1965-1966.

Lecturer, New York University School of Social Work, 1965-1966.

Clinical Assistant Professor, Department of Public Health, Cornell University Medical College, 1964-1965.

Clinical Instructor, Department of Medicine, Cornell University Medical College, 1961-1965.

Clinical Instructor, Department of Public Health, Cornell University Medical College, 1961-1964.

Trainee, United States Public Health Service, Infectious Disease, Cornell University Medical College, 1959-1961.