Shouldn't you buy social security if you have a medical history?

First of all, the two have nothing to do with each other, and both can be bought.

Secondly, if it is an individual, social security usually includes basic medical care, pension and maternity. Basic medical care will not take effect until one year after payment, that is to say, hospitalization will not take place until one year after medical payment.

If you sign a labor contract, the employer must also buy you social security.

I hope it works for you!