$950 for two blood tests?

I turned 26 in April, so I’m new to the whole insurance thing. When I was on my parents’ insurance, they’d just hand me the bills for whatever I owed, so I never looked much into it. All I know is that the old plan I was on under United Healthcare seemed like it never covered much of anything, but even so, I never had to pay as much for blood tests as I do under my supposed “good” insurance now.

I have an Independence Blue Cross Personal Choice Plan through my employer, and I pay extra for the zero deductible plan. I do have a prolactinoma that, while not worrying, I do routinely get blood tests for to ensure my prolactin stays in the acceptable range. I just got a notice that I had a $320 payment overdue, so I logged into my account, and lo and behold, I have two bills from bloodwork over the last few months: one for $320, the other for $620. The insurance paid $120 on one and like $18 on the other. What gives? I have a legit medical need for these tests, and I thought beyond my premiums and co-pays I’d be set with the no-deductible plan.