Shortly after graduation, he became involved in liver transplant program of the Department of General, Transplant and Liver Surgery of the Medical University of Warsaw. Dr Grąt started residency in general surgery at the Department of General, Transplant and Liver Surgery.
On 2018, he received a grant from a National Science Center of the Republic of Poland for a project focused on risk factors for the development of incisional hernias after abdominal operations performed through transverse incisions. Until now, Michał Grąt authored a total of 62 articles (25 as first author) with a cumulative impact factor of 86.7, in such prestigious journals as Annals of Surgery, Annals of Surgical Oncology, Clinical Nutrition, Transplantation, Scientific Reports, among other. He received several awards, including scholarships of the Minister of Health of the Republic of Poland and awards of the International Liver Transplantation Society, Polish Academy of Sciences, and Polish Medical Association. Dr Grąt serves as a member of the Editorial Board of the World Journal of Gastroenterology.