Can a company that has agreed to accept your out of network health insurance bill you for the difference?

I went to a physician that worked in surgery with my husband. He agreed to accept me as a patient and take what my insurance paid as payment. It was out of network and he knew that. I am now being harassed by a collection agency for a bill I should have never received.
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Well, did they say they'd accept the RATE that the insurance paid? Because most likely, if it was out of network, you had a deductible or coinsurance percentage that you had to pay. For instance, he charged $5000, the insurance rate was $3000, and your deductible and coinsurnace added up to $1000 of that, leaving the insurance paying $2000. They may have agreed to accept that rate, which means they would've written off that $2000 difference between what they normally ask for and what the insurance said would be allowed (usually called Usual and Customary rate, or Usual and Reasonable rate), but they'd still expect you to pay what the insurance says you're responsible for (the $1000). Or if you had more than a $3000 deductible, the insurance would say they allow the $3000 and are applying it all to your deductible, and they are paying nothing....so again, the doctor would've agreed to only bill you for what the insurance says, and they'd write off the $2000 difference. If you didn't have responsibility according to your insurance company, then definitely take this up with the drs office like the other answers suggest.
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