Jonathan lived in Westport, Connecticut with Iris Greenfield and their three children, Zach, Skye and Josie. Once dubbed “the most interesting person in Westport,” Jonathan and Iris lead a busy and active life, and found time both for themselves and their children. Jonathan participated in a handful of triathlons in 2018, was a year-round surfer, loved jiujitsu, has traveled the world making documentary films for the Westdeustcher Rundfunk (WDR) in Germany, was a freelance photographer for the New York Times, and was a certified tea specialist and teacher for the Specialty Tea Institute.

In December, 2018, Jonathan was diagnosed with amyotrophic lateral sclerosis (often referred to as ALS or Lou Gehrig’s Disease), a neurodegenerative disease that affects nerve cells in the brain and spinal cord. Jonathan fell within the approximately 10% of cases of ALS that are considered “familial ALS.” Jonathan’s father Dr. Hyman Greenfield passed away in September 2015 following complications from ALS, and his brother Seth Greenfield was diagnosed with ALS in the fall of 2018.