Usage of AT (Active Treatment ) Modifier

by | Apr 6, 2016 | CPT modifiers

The Active Treatment (AT) modifier defines the difference between active treatment and maintenance treatment. 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 is used only when chiropractors bill for active/corrective treatment (acute and chronic care). The 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 AT modifier if active/corrective treatment is being performed; and 2. The AT modifier should not be used if maintenance therapy is being performed. MACs deny chiropractic claims for 98940/98941/98942, with a date of service on or after October 1, 2004, that does not contain the AT modifier.


The following categories help determine coverage of treatment.

1. Acute subluxation: A patient’s condition is considered acute when the patient is being treated for a new injury (identified by x-ray or physical examination). (See SE1601 for details of the x-ray and examination requirements.) The result of chiropractic manipulation is expected to be an improvement in, or arrest of progression of, the patient’s condition.

2. Chronic subluxation: 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); however, 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.

Both of the above scenarios are covered by CMS as long as there is active treatment which is well documented and improvement is expected.

Maintenance: Maintenance therapy includes services that seek to prevent disease, promote health and prolong and enhance the quality of life, or 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. The AT modifier must not be placed on the claim when
maintenance therapy has been provided. Chiropractors should consider obtaining an Advance Beneficiary Notice (ABN) from beneficiaries in the event of a denial of a claim.


Key Points

For Medicare purposes, a chiropractor must place an AT modifier on a claim when providing active/corrective treatment to treat acute or chronic subluxation. However, the presence of the AT modifier may not in all instances indicate that the service is reasonable and necessary. As always, MACs may deny if appropriate after medical review determines that the medical record does not support active/corrective treatment.