So CBL had lots of posts about this issue, and lots of detail (if this all fascinates you, try this link, which has more links, where you'll find still more links, etc.), but frankly, the question is really simple:
You're a plaintiff in a tort. case. You have bills from the doctor and hospital for $100K. Your health insurance carrier pays them $15K, and they accept that as payment in full. What do you get at trial, $100k in special damages, or $15K in special damages?
CBL's collegeague Georges Haddad went to the Cal Supremes hearing on this, and his crystal ball said the defense would win -- the answer was $15K.
Georges didn't get the last word -- the Cal Supremes did. And turns out, Georges was right:
When a tortiously injured person receives medical care for his or her injuries, the provider of that care often accepts as full payment, pursuant to a preexisting contract with the injured person‘s health insurer, an amount less than that stated in the provider‘s bill. In that circumstance, may the injured person recover from the tortfeasor, as economic damages for past medical expenses, the undiscounted sum stated in the provider‘s bill but never paid by or on behalf of the injured person? We hold no such recovery is allowed, for the simple reason that the injured plaintiff did not suffer any economic loss in that amount.
Howell v. Hamilton Meats (August 18, 2011) ___ Cal.4th ___. End of story. Plaintiff gets what was paid, not what was billed. Correct result, sez CBL.