He started his professional career at the Clinic of Pneumology and Phthisiology in Martin in 2001, after graduating from the Jessenius Faculty of Medicine of the Comenius University in Martin. In his professional career, he is dominantly devoted to bronchology. In 2011, he introduced endobronchial ultrasonography into routine clinical practice at University Hospital martin ( UHM). In January 2013, he became the head of the Clinic of Pneumology and Phthisiology of UHM and Jesenius Faculty of Medicine UK (JFM UK).

He was the first in the Slovak Republic to use cryotherapy and cryocautery in bronchology in the treatment of lung cancer, during the routine performance of endobronchial biopsies and transbronchial cryobiopsies of the lungs. In 2017, he became the head of the UHM Medical and Preventive Care Department. In this function and as the head of the Clinic of Pneumology and Physiology, he significantly participated in the management of the COVID-19 pandemic at the Martin University Hospital. He came up with the idea of using telemedicine in the treatment of the disease COVID-19 in the home environment. Together with his colleagues and programmers, they developed an application that they started using during the second wave of the COVID-19 pandemic.

In 2021, he received the Master of Healthcare Administration (MHA) management degree. In the Medical newspaper poll, he was awarded the Top doctor in Slovakia in the category of pulmonologist and phthisologist for his professional work. In the same year, the Žilina self-governing region and the Žilina self-governing region  Youth Council awarded him an award for active citizenship and humanity 2021 in the Top Act of Humanity category.

After the transformation of the UHM leadership structure in 2022, he became the deputy of curative and preventive care for internal medicine disciplines and SVALZy. He worked in this capacity until the successful selection procedure for the position of statutory director - director of the Martin University Hospital. At the same time, Ivan Kocan also works in the executive committee of the Slovak Pneumophthizeological Society and in the expert working group of the Ministry of Health of the Slovak Republic for the optimization of the hospital network.