In personal injury law, a medical provider will often ask for a "Letter of Protection" from the attorney representing the injured person. So what is the attorney giving when they issue a "Letter of Protection" (also sometimes called an "LOP")?
An LOP is a letter or other written documentation issued by a lawyer or law firm to a medical provider agreeing that in the event of a settlement or recovery in favor of the injured person, no funds will be released to the injured person until the medical provider's bill has been paid from the proceeds recovered. In simple terms, it's a guarantee by the attorney that the medical provider will be paid from the recovery.
So why is an LOP important? Often after a person is injured in an accident they need medical treatment. Sometimes that treatment is not covered, or not covered in full, by insurance. In such a case, the medical provider may be reluctant to provide care or treatment without some form of assurance that they will be paid. The LOP usually provides that needed assurance.
By way of example, consider a case where John slips and falls in a shopping center parking lot due to an unforeseen danger. He breaks his wrist and needs surgery. However, John has no insurance--or his insurance will not cover all of his medical expenses. The shopping center owner denies any responsibility and therefore offers no help. John's only way of getting treatment may be to go to a physician who will accept an LOP. John's lawyer issues the LOP to the physician, John gets treated, and afterwards pursues a lawsuit against the property owner. If a recovery is made, before John gets any money, his provider gets paid from the recovery.