Dr. Quimby's major research interests are HIV/AIDS, substance abuse, mental health services and juvenile/criminal justice issues. He was the Principal Investigator of a NIDA initiative to stimulate drug abuse research at Historically Black Colleges and Universities. Dr. Quimby has been the Co-Principal Investigator of Washington, D.C., research studies and demonstration projects funded by the National Institute on Alcoholism and Alcohol Abuse, National Institute on Mental Health, and Substance Abuse and Mental Health Services Administration.  In conjunction with the New-Hampshire-Dartmouth Psychiatric Research Center (PRC), these have included homelessness, HIV/AIDS, mental illness, supported employment and vocational rehabilitation. Dr. Quimby directs the Community Technical Assistance Project, a community-based research and service learning program.

He served as a lead ethnographer for the Rapid Assessment, Response and Evaluation HIV/AIDS research and prevention initiative of the U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, and the Health Departments of the District of Columbia and Baltimore City. Dr. Quimby is a consultant with the D.C. Department of Mental Health and PRC on evidence-based practices and supported employment programs for persons with severe mental illness. He is also a reviewer for NIDA, NIMH and the Department of Justice.