<<Disclaimer: Verify this information before applying it to your situation.>>

My suggestion is to find out from the billing service for the lab what
the codes actually mean and then hassle the insurance company.  Dont
accept the initial response and keep going higher in the insurnace
company. Kepp records of who you speakj to and what they told you. put as
much as possible in writing.  $20 dollars is rediculous. 100 to 200 is
usual.  Good luck in your battle with the insurance company.
joe murray