 suggestion
If your husband was good about keeping the books he got when he signed up on the plan, that would be a good place to start. If he doesn't have them, his HR department should be able to get him a copy or at least let him borrow one.
Make sure you're looking at the books from the current plan year though, things change wildly sometimes.
you could just call the customer care number on the back of your card, but be forewarned, they will tell you whether you're covered or not, but are very careful to say that telling you your covered is not an official approval for treatment.
Some insurances require approval for certain kinds of care. The ones that come readily to mind is physical therapy and counseling.
If you're planning to do this and are nervous, ask themm what you would need to do to get the approval in writing, that way you have it if they ever start arguing about it.
Do be careful and review your coverage every year though. As insurance costs go up, companies start dropping care they consider unessential in order to keep the cost of insurance for the larger group down. So if your journey takes you through from one plan year to the next, you may need to get your approvals all over again.
A good office manager (at your doctor's office) should be able to help with some of this as well. | 
Insurance question 
