The first and foremost reason is for your child’s protection. Given that he/she has serious medical needs puts him/her in the risk category by the insurance companies. Many HMOs have caps on their spending, so, for some unfortunate reason when your child’s bill exceeds the cap you have a secondary source to tap into. Usually Medi-Cal agrees to pay most of the bills which the HMOs have rejected except if they were deemed to be unwanted procedures.