Even though the Chiro may dispute this.....Spinal "decompression" is a fancy way of saying lumbar traction. It's 97012 - Mechanical traction. The insurance reimbursement isn't much for this service. But I'm sure the Chiro has a contract with the patient to pay much more for the service.
As the biller, make sure you understand 100% of the contract the doctor has with the insurance company and the patient so you're not caught up in any unintended billing fraud.