This is pretty basic information that you especially and the doctor particularly needs to understand:
Scenario - Patient has a $1500 deductible, $25 co pay, (and just for example) 20 visits allowed per year. And the doctor is participating with NO special contract negotiations.
The patient has to meet the deductible 1st. Deductible is reduced every time they go to ANY doctor, have labs done, or studies taken. It includes ALL medical services. It doesn't matter what the co-pay or co-insurance is until the deductible is met, the patient will owe the whole allowed amount (as determined by the insurance company) until the deductible is met.
Once the deductible is met, THEN the $25 co-pay per visit kicks in. They pay $25 per visit, the insurance company will pay the rest.
If they go over the 20 visits allowed (or $ amount per year allowed, or whatever limitations there are on the insurance policy if any) then they owe the total amount of the visit again.
While a patient is meeting their deductible, it's always best to AT LEAST collect the co-pay. You KNOW they will owe that much. That way if they meet their deductible and don't tell you, you won't have so much to refund. Also, if they can't pay the full amount of each visit at the time of service their bill won't be so huge.
I hope this helps. This is pretty basic information, but really important for you and the doctor to understand if for no other reason than YOU WILL have to explain it to the patient in a way they can understand. And I can't tell you how many people don't understand their own insurance and what all the terms mean.