Answer
The debtor must be sued in the court of jurisdication in their state. If the plaintiff/creditor prevails a judgment will be entered in their favor. The judgment can then be executed against property belonging to the debtor in accordance with the governing state laws.
Collection agencies often use arbitration where it concerns medical bills.
Arbitration allows the creditor to bypass normal court procedures by means of submitting valid evidence of the debt to the arbitration board. The debtor will be informed of the action and given 30 days to submit a written response. Even when an arbitration award is granted to the creditor said creditor must still file the action in the proper state court to receive a writ of judgment.

