Re: Rose Marie
Your state law would likely be what determines if you have to keep him on your insurance.
Once a legal separation is filed, and perhaps once divorce is filed, you generally have a financial firewall. Thus if he racks up debt after one of those events you probably aren't responsible. However, these are all questions for an atty. You should talk to one asap. Most will give a free consult of 15-30 minutes where you can get these questions answered.
In my state the answer is no, you don't have to have a spouse on your health insurance at all.
Keep in mind you have a deductible and max out of pocket which could be a lot higher with him on it. So if you do have him on it, he should be covering those differences as well as his portion of the premiums.
If he is working, he should be able to switch to his employer's health plan without a problem once a legal separation or divorce happens.