Like any legal document, the subrogation letter can be confusing if you aren't familiar with the term or the process. Click here to learn more about it!Insurance companies can utilize this letter template to seek reimbursement from the person or entity legally responsible for a loss. I received a subrogation letter for medical treatment for a dog bite, but the owner was homeless. Do I need to hire an attorney? Healthcare subrogation begins where an injury occurs as a result of third-party negligence. If you are to recover money from a third party in a personal injury claim and the health insurance company has paid for your care they're entitled to be reimbursed. What is subrogation? Why am I being asked to waive it? Shortly after the initial insurance claims, I received the forms to fill out for subrogation.