Got a surprise bill

Hi all – I am a 27M who has health insurance through work – blue cross blue shield of Massachusetts. I have the blue care elect preferred.

I went to the gastro a few weeks ago because I’ve been having stomach issues. They did blood work and sent me home with a stool sample kit. I did the “microbiology” test and dropped it off at a labcorp location over a month ago. I received a bill in the mail today for $819 because the microbiology test is not covered by my insurance.

My insurance was reviewed by the gastro 2+ times (when I submitted the form for the appointment & when I arrived for the visit) and labcorp reviewed my insurance when I checked in to drop my sample off. At no single point did anyone care to mention that this would be such a large charge that isn’t covered by my insurance – obviously I don’t know if they even knew but my insurance was looked at and checked a lot.

When checking the claim document for that visit it states “BENEFITS ARE NOT AVAILABLE BECAUSE THIS SERVICE EITHER DOES NOT MEET OUR MEDICAL TECHNOLOGY ASSESSMENT CRITERIA OR OUR MEDICAL POLICY GUIDELINES.”
Why would a microbiology test ordered by a gastro not be covered???

Is there anything I can do to fight this? I’m planning on calling my insurance and labcorp tomorrow morning but $819 is a lot and this sucks and the fact that there was no transparency sucks even more.

Any help is appreciated. Thank you.