Not to totally freak you out, but just letting you know that insurance companies are known to cover something "by accident" but then realize their mistake and then "readjust" their payment and then the office will give you a bill. I am going through this right now with my allergy clinic. My insurance covered a bunch of my allergy shots without applying my $30 specialist copay. I thought I misunderstood the policy and my copay didn't apply, but I was wrong. I am appealing the "adjustment" since it was their mistake to cover them in the first place, but it's looking unlikely that I will win (because it's "my responsibility" to know everything about my policy and "correct" their mistakes). So, even though you don't want them to rescind payment, it might be worth a strategic call; without referring to them as "fertility drugs" maybe just call them hormones to fix a hormonal imbalance (or something). In any case, I wouldn't spend the money you thought you'd budgeted for drugs on another cycle until you know for sure you're not going to get a huge bill later on.