AT Modifier

Q:   What is the status of the "AT" Modifier requirement under Medicare?

A:   Effective October 1, 2004, the AT Modifier is required under Medicare billing to receive reimbursement for CPT codes 98940-98942. 

For Medicare purposes, the AT modifier shall now be used only when chiropractors bill for active/corrective treatment (acute and chronic care). This policy requires the following:
  1. Every chiropractic claim for 98940/98941/98942, with a date of service on or after October 1, 2004, should include the Active Treatment (AT) modifier if active/corrective treatment is being performed; AND
  2. The AT modifier should not be used if maintenance therapy is being performed. Contractors shall deny a chiropractic claim for 98940/98941/98942, with a date of service on or after October 1, 2004, that does not contain the AT modifier.
CMS has also revised the following definitions, which should prove helpful in determining the type of treatment being rendered.
  1. CMS defines Acute as: "A patient's condition is considered acute when the patient is being treated for a new injury, identified by x-ray or physical exam as specified above. The result of chiropractic manipulation is expected to be an improvement in, or arrest of progression of, the patient's condition."
  2. CMS defines Chronic as: "A patient's condition is considered chronic when it is not expected to significantly improve or be resolved with further treatment (as is the case with an acute condition), but where the continued therapy can be expected to result in some functional improvement. Once the clinical status has remained stable for a given condition, without expectation of additional objective clinical improvements, further manipulative treatment is considered maintenance therapy and is not covered."
  3. CMS defines Maintenance Therapy as: "Chiropractic maintenance therapy is not considered to be medically reasonable or necessary under the Medicare program, and is therefore not payable. Maintenance therapy is defined as a treatment plan that seeks to prevent disease, promote health, and prolong and enhance the quality of life; or therapy that is performed to maintain or prevent deterioration of a chronic condition. When further clinical improvement cannot reasonably be expected from continuous ongoing care, and the chiropractic treatment becomes supportive rather than corrective in nature, the treatment is then considered maintenance therapy."