Wisconsin Law allows parties to file for legal separation if "the marriage is broken" but not irretrievably broken. Many times, parties will file for legal separation for precisely the reason that you list, to undo finances but to maintain health insurance coverage. If the parties choose, they may move the court within a year after the entry of the legal separation order for a judgment of divorce.
Just a caution, however, check with your medical insurance provider to determine whether a legal separation will void your spouse's health insurance coverage under the terms of the policy.
Be very careful about insurance providers; they are getting much more strict on allowing even legally separated spouses from remaining on their insurance. Usually only government employers or very large corporations have the kind of coverage that allows such a continuation.
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