Generally speaking, under an standard Obamacare plan, you should not have to pay any copays or coinsurance on any essential benefits once you have met your out-of-pocket maximum (Obamacarefacts.com).
In practice, however, there are a few complicating factors:
- Did the money you spend so far count towards your out-of-pocket maximum? If you payed for uncovered out-of-network care, or other non essential benefits, your insurance company may not count that towards your maximum out of pocket expenses.
- Have all the claims been processed? While you often pay your co-pay at the time of service, the insurance claims process is much slower. Your insurance company may not have caught up with all of your bills, and so have not yet calculated your total out-of-pocket costs so far.
- Is your insurance company making a mistake? Be sure to review your EOBs and bills and make sure everything seems to match up and make sense according to your insurance contract. Insurance companies can make mistakes, and those mistakes usually aren't in your favor (at least that is my personal experience). Keep an eye out for possible mistakes, and call your insurance company if you think you have found one.
- Even if your insurance company doesn't think you owe a co-pay, your doctor doesn't know that: Your doctor's office probably just bills whatever co-pay they see written on your card. It is unlikely that they can tell that you already met your maximum-out-of-pocket until the claim is processed by your insurance company. If you know you met your maximum-out-of-pocket already, just explain that to the receptionist (or whoever does the billing) when they ask you for your co-pay.
As for unnecessary co-pays you already payed: In my experience, the insurance company will pay the claim without applying a co-pay, and leave it up to the doctor to refund your co-pay. However, you should call your insurance company to verify this. If they do tell you to get a refund from your doctors office, wait until you get the EOB for the vist (which should show you owe no copay) and bring it in to your doctor's office when you ask for a refund.