Those plans have group numbers on them. That is how you can tell. Also, those plans come with high deductibles. That is a red flag to the physician.
High deductible plans aren’t the same as subsidized plans. I have a high deductible plan, and no subsidy, and no additional paperwork for doctors. I’ve never heard of a doctor caring about anything other than the health insurance company, and they don’t even know what the specifics of your plan until you are in the office after they’ve taken your appointment.