An insured person who has changed health insurance company is obliged to notify his employer by January 8, 2025. If he has more than one, he must report the change to everyone. This follows from the information of the Health Care Supervision Office and all three health insurance companies, which they published on the website.
It is also necessary by this date notify the relevant health insurance company of the payer of the insurance premium if, after submitting the application, there was a change in the payer of the insurance premium that he indicated on the application. The insured, on the contrary, is not obliged to deregister from the previous health insurance company. He does not even have to return the original insurance card.