:::At least as used in the US, "single-payer" means that there is only one primary payment system (typically government run).  Taken by itself, it doesn't say anything else about the system.  Delivery of services may or may not be provided through the private market.  It also doesn't require that all payments be run through the "single" system.  Incidental payments such as modest deductibles and copayments aren't seen as inconsistent with the term "single-payer."  Other, non-routine sources of payment, such as product liability payments covering health care for injuries  resulting from a defective product, aren't seen as inconsistent either. In some respects the usage is a bit loose, but it does speak to a basic question - are there multiple finance or insurance schemes funding health care for the population involved, or just one?  If the answer is "just one," then most people in the US would call it a single-payer system regardless of the other details of the system.