The rehab facility is liable for your son's injury.When your son completes his medical treatment and is released by the doctor or is declared by the doctor to be permanent and stationary, which means having reached a point in his medical treatment where no further improvement is anticipated, obtain your son's medical bills and medical reports.Your son's personal injury claim filed with the insurance carrier for the rehab facility should include his medical bills and medical reports.  Compensation for the medical bills is straight reimbursement.  The medical reports will document the nature and extent of your son's injury and will be used to determine compensation for pain and suffering, which is an amount in addition to the medical bills.If the case is settled with the insurance carrier for the rehab facility, NO lawssuit is filed.If you are dissatisfied with settlement offers from the insurance carrier for the rehab facility, reject the settlement offers and file a lawsuit for negligence against the rehab facility on behalf of your son.  If your son is a minor, you will need to be appointed guardian ad litem to file a lawsuit on his behalf because a minor cannot file a lawsuit himself.If the case is NOT settled with the insurance carrier for the rehab facility, your son's lawsuit for negligence against the rehab facility must be filed prior to the expiration of the applicable statute of limitations or your son will lose his rights forever in the matter.