Hi isa,
Your questions are pretty easy:
1) Physicians are paid in a couple of different ways: either only by the insurance co, only by the pt (when they have no insurance or deductibles) or by the insurance company and the patient. If the patient has a "co-pay," this is always paid to the physician. If it is a set amount (say $40 per visit), then the pt pays this at the time of treatment (tx). If it is a percentage (say 30% of the total), the physician will bill the pt and the insurance co. The physician then gets paid 4-8 weeks after tx (if all is going well). Or, if it is an HMO-style plan, the pt pays nothing to the doc (just to the insurance co) and the physician is paid by the insurance co.
In traditional ("indemnity") insurance, anything the physician billed for was paid at 100% of the cost (billed rate) by the insurance company. This system "encouraged" physicians to do every procedure and to charge high rates for each test or procedure. Eventually, the costs spiraled out of control and health care expenditures in the U.S. were at least 2-3Xs as much as any other industrialized nation (as a percentage of GDP - I think).
As an aside, if you're asking how physicians get paid certain levels of compensation, that is pretty tricky. It all depends on how good they are at negotiating with payers (insurance companies), what levels of reimbursement they are willing to accept, etc. For example, a lot of specialists routinely get paid 50-60%of their actual fees.
2) Your second question re: PPO vs. POS. There is not much of a difference between them, except that POS's have an HMO component. Usually a POS has three levels of care -- the first level simulates an HMO and is the cheapest for the pt (you go to a primary care doc and if you need to see a specialist, he/she must give you an authorization and referral); the second level allows you to see a specialist in the network on your own without a referral (but you pay more); the third level lets you see anyone out of the network (but you pay for MOST of the cost - say 80%). A PPO is the same for the most part, but you do not have an assigned primary care doc and you do not need referrals (i.e., there is not an HMO component to the plan). The PPOs are typically more expensive because the pt directs his/her care (rather than a primary care doc) and this "leads" to more utilization of costlier providers (in theory).
Hope this is helpful. Good luck on interviews!
-- Becky
