They might try to file suit where the contract was signed or where the consumer resides - unless is an oral agreement - many, if not most, medical collections fall under oral agreements:
Section 811 provides that a debt collector may sue a consumer only in the judicial district where the consumer resides or signed the contract sued upon, except that an action to enforce a security interest in real property which secures the obligation must be brought where the property is located.
[...]
Where services were provided pursuant to an oral agreement, the debt collector may sue only where the consumer resides. He may not sue where services were performed (if that is different from the consumer's residence), because that is not included as permissible forum location by this provision.
