On October 1, 2019 the Act of July 31, 2019 on supplementary benefit for persons who are unable to exist independently, commonly referred to as the "500 plus act on the disabled people", entered into force. In accordance with the will of the Legislator, pensions institutions including the Social Insurance Institution (ZUS) are the competent authority to examine applications for supplementary benefit. One of the conditions to get that benefit is having a certificate of the inability to an independent existence which is issued in ZUS by evaluating doctors and medical boards. Therefore in this article we would like to look closely at the aspects of certification of the inability to an independent existence in ZUS. From October 1, 2019 not only insured persons may apply for a certificate of the inability to an independent existence. According to the new Act supplementary benefit may be applied for by anyone who is at least 18 years old and the sum of this person's cash benefits financed from public funds other than one-offs does not exceed PLN 1,600. The answer to the question of who is incapable of independent existence can be found in the Act of 17 December 1998 on pension benefits from the Social Insurance Fund. This is the basis to issue medical opinions in ZUS.