Assessing the body’s reserves (rehabilitation potential) to predict the risk of developing diseases or their outcomes (rehabilitation prognosis) is very important. This provides an opportunity for an individual approach to the patient. The proposed method for assessing the basic component of the rehabilitation potential - the morpho-functional index (MFI), developed using computer modeling methods, allows you to obtain accurate (quantitative) and objective information about the state of the human body at the starting point of the examination and to monitor the course of the process in dynamics. The effectiveness of the use of the MFI indicator is confirmed by examples of its use in clinical practice. © 2020, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.