Use of the AT modifier for Chiropractic Billing (New Information Along with Information in MM3449)
The Active Treatment (AT) modifier was developed to clearly define the difference between active treatment and maintenance treatment. Medicare pays only for active/corrective treatment to correct acute or chronic subluxation. Medicare does not pay for maintenance therapy. Claims should include a primary diagnosis of subluxation and a secondary diagnosis that reflects the patient's neuromusculoskeletal condition. The patient's medical record should support the services you are billing.