AT: Active treatment modifier

The Active Treatment (AT) modifier was developed to clearly define the difference between active treatment and maintenance treatment. The Centers for Medicare and Medicaid Services (CMS) has required the AT modifier on chiropractic codes since 2004. Now Priority Health is aligning with CMS for all other products.

AT modifier is required when:

AT should be appended to chiropractic CPT codes 98940, 98941 and, 98942 to identify chiropractic services that are covered according to our medical policy for commercial products. The AT modifier indicates that services are for acute conditions and allows for coverage of the chiropractic services.

UPDATED: Effective October 1, 2018, Services reported without the AT modifier will be denied for non-coverage per our policy.

Do not use the AT modifier:

For chronic conditions or treatment associated of maintenance of chronic conditions.

Also see:

Medical policy: Habilitative and Rehabilitative Services - 91318

In the Provider Center: Procedures & services > Medical/surgical > Manipulations

MLN Matters article SE1602, Use of the AT modifier for chiropractic billing (PDF)