Subrogation might occur if one carrier has settled but thinks another insurer is also liable. Subrogation might occur if an excess carrier has paid a claim that the primary carrier should have paid in part. In addition, statutes may provide for subrogation rights as well. There are lawyers who do nothing but subrogation cases. Sometimes these lawyers will get a few dozen cases at a time from an insurance company.
Many people are confused about the difference between subrogation and contribution.
It is neither a contract nor a tort remedy, but a right based on principles of fairness. Contribution and subrogation overlap, but there are instances where one may be applicable and not the other. Assignments are usually based on a contractual agreement between two parties. As such, an assignment differs from a subrogation or contribution in that an assignment is generally not based on the same legal principles of fairness. An insurance company may seek a voluntary assignment of rights from an insured or another person if the insurer thinks its position in court as an assignee will be stronger than as a subrogee.