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