Reasonable value of medical services is the amount paid rather than the amount billed for both past (Howell v. Hamilton Meats & Provisions, Inc. (2011) 52 Cal.4th, 541, 556) and future (Corenbaum v. Lampkin (2013) 215 Cal.App.4th 1308, 1330) medical treatment. Further, damages need to be reasonably certain to be recoverable. Cal. Code Civ. Proc.§§3283, 3359. So how does one establish or challenge future damages and the reimbursement rate likely paid?