Hello dear EFers.

I've searched the forums for this, but to no avail.

I am planning on being in CH in January. Thus I'll get a basic insurance with some insurance company.

My wife and 9yo son will join me sometime during summer.
At this point I'd have to add them to my insurance as well.

Is this scenario possible, or I would have to make an insurance plan with all 3 of us from the beginning?

As always, thanks in advance.