There is a very frequent confusion among those who arrive in Switzerland: they believe that LAMal, the mandatory health insurance, covers everything. Covers medical expenses, yes. The doctor, the hospital, the prescription drugs. But it doesn't pay you a franc of your salary while you can't work. That's managed by something else.
When you take sick leave in Switzerland, who pays you depends on your contract and the canton. The law obliges the employer to continue paying the salary for a minimum time according to article 324a of the Code of Obligations. The first year of the contract is three weeks. From the second, progressively more weeks according to the years of service. There are different tables depending on the canton: the Bernese scale, the Basel scale, and so on. After that period, if there is nothing else, the employer is not required to follow.
And that's where the IJM comes in, the assurance indemnités journalières maladie. It is a collective insurance that many employers take out, often because it is required by the collective agreement of their sector. If your company has IJM, you receive 80% of your salary from the first or third day off, up to a maximum of 720 days in a 900-day period. It is what is considered the standard of protection in Switzerland, but it is not guaranteed by law for everyone.
What is worth asking HR directly is whether the company has IJM. Many people have been working in the same place for years and do not know it. And he discovers it when he has a casualty that lengthens and things start to get serious.