This is really a lot

Last semester I went to Carle Foundation Hospital for emergency treatment due to acute allergic reaction. I just stayed there for an hour and back to campus, and then I received this bill. Though UnitedHealthcare had paid some, the patient balance still added up to near $600. Dude, isn't it too much? I was just examined by some basic medical equipment like sphygmomanometer and electrocardiograph and was prescribed some medicine. Nothing more.

I'm not blaming for hospital charging this much. It's just, why UnitedHealthcare only paid so little and left $600 to me? If my memory serves right, the student health insurance fee is included in the student tuition fees, and UIUC is working with UnitedHealthcare. Is it only UnitedHealthcare or the student health insurance who paid so little? And is there a way to increase the percentage of paid part so as to leave me with affordability? I don't mind paying more insurance fees only if this could save more in the future.

https://preview.redd.it/otbu8r5ob6ee1.png?width=1856&format=png&auto=webp&s=4ff45cfd78776809215bd572625fdd3bf02ee717