From the way the author explains the data they are required to enter, it sounds like a HCFA 1500 form they are completing, which is a standardized form. It is

From the way the author explains the data they are required to enter, it sounds like a HCFA 1500 form they are completing, which is a standardized form. It is not simple for first timers, and it looks like UHC's web-based implementation might overcomplicate things. Youtube has some good overviews of how to complete the form. With the actual paper form in front of you it makes more sense (the form also includes definitions and instructions on the back). Many providers will provide the completed form for you after payment for easier reimbursement, but submitting paper as opposed to filing electronically, at the expense of a quicker turn around time.