As of 2020, Muller is senior advisor and co-founder (with Ramon Murphy and Philip J. Landrigan) of The Arnhold Global Health Institute, a division of The Mount Sinai Medical Center dedicated to finding evidence-based solutions to global health problems.
[6] Muller joined the faculty at the Icahn School of Medicine at Mount Sinai in 1993.
In that role he addressed prevention of suicide, racism and curtaining debt among medical students.
[11] The VDP serves approximately 1,000 homebound elderly patients annually[12] and trains approximately 200 medical students, residents, and fellows annually in the provision of house calls and home care.
He received the AAMC Spencer Foreman Award for Outstanding Community Service in 2009.