There are some issues that the law deals with and other issues that the law doesn't address. Although every state has a statute of limitations which defines how much time must elapse before a creditor is precluded from suing on a debt, I am not aware of any law requiring a creditor to bill within a certain amount of time. How has the delay harmed you would be the argument you would have to make to the court to utilize this as a defense to paying the debt. Hope this perspective helps!
If you did not agree on an amount to pay the surgeon then you may not have complete liability for the balance if the court were to deem it excessive based upon the customary and reasonable charges. The statute of limitations will expire six years after the last payment was received, which is a long time away. If you are sued, I would recommend bringing Third Party actions against your insurance carriers, but if you are unable to settle for less than the full balance due, you will likely need to defend the action in court.
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