It's necessary for companies to set up health insurance coverage for their employees.
It's necessary for companies to enroll their employees in their health insurance.
ご質問ありがとうございます。
「set up coverage」を使いたいなら、そのまま難しですが、「set up health insurance coverage」ならできます。
英文は下記の通りになります。
「It's necessary for companies to set up health insurance coverage for their employees.」
「set up coverage」以外、別の言い方で「enroll」と言います。そうすると、「It's necessary for companies to enroll their employees in their health insurance.」と言えます。
ご参考になれば幸いです。