Difficult to answer and google search did not help.

I think you are talking about 'sliding scale' fees paid to county clinics/labs. Those fees are determined based on your income and fees are determined on the spot (hopefully, same in CA too). Not sure, but I think your information is not verified against federal database (like SNAP) otherwise it would take some time to process. Probably you do not need worry, but things are getting difficult these days. Using Medi-Cal probably would have made your situation worse.

Sorry for a not helpful answer. Just sharing thoughts. Best wishes!