What is the ruling on using the health insurance card provided by the employer, which allows for the addition of some family members?

If the employer pays the treatment bill directly to the hospital, then there is no harm in the aforementioned health insurance. However, if it subscribes to an insurance company, then there is a detailed explanation: If it is commercial insurance, it is forbidden and it is not permissible to subscribe to it voluntarily. If it is cooperative, Takaful (mutual) Islamic insurance, then it is permissible. If the insurance is mandatory for the employer by virtue of the contract, then there is no harm upon the employee in receiving his right, and in this case, the sin falls upon the employer.