If it is group health insurance they have to insure the whole group. They cannot cherry pick, or take the cream of the crop, if you will, under a group plan, and then the cost is spread over the whole group. They all have to pay equally, unless you have family members whom you want covered, and then, of course, YOU would have to pay extra for that family member(s) coverage. Thats the way it worked for any of the companys I worked for. I will say again, if they accept the group, then all will be covered, including any pre-existing conditions in any of the group, or their family members.
Good luck Bonnie