The fourth of four male siblings, he decided to pursue a career in medicine after the long illness and death of his father from familial cardiomyopathy at age 52.
[6] In the first year at those positions Montgomery was lead physician in what Johns Hopkins called the world's first simultaneous "triple swap" kidney transplant operation.
[10] Montgomery helped develop a laparoscopic method for removing a kidney from a living donor which became common practice.
The kidney was engineered by Revivicor, Inc., a subsidiary of United Therapeutics, to remove the alpha-gal sugar, which is associated with hyperacute rejection.
[11] In summer 2023, Montgomery led the longest study of a genetically engineered kidney xenotransplant in a human body to date.