The company issued a social security card, and I want to change to a designated hospital. The personnel said that the social security card cannot be changed. Is it true?/You don't say.

That's only half right. There are 23 3A hospitals in Beijing that do not need to be designated. You can see a doctor at any time with your social security card and blueprint. If the hospital you see is neither in the above-mentioned hospital nor in the designated hospital you reported, you can only change it once a year. You have to ask the social security office for the details of changing the corresponding social security card!