Modifier AT

Acute or Active Treatment


This Chiropractic only modifier tells Medicare that this treatment should be covered as acute or active treatment.

Correct Use

  • Chiropractic manual manipulation of spine service for acute therapy
    • Involves CPTs 98940, 98941, and 98942 only
  • Corrective treatment supporting the manipulation
    • Not considered Maintenance therapy (see modifier GA)
    • Documentation MUST support acute/active/corrective treatment

Incorrect Use

  • Do not bill modifier AT with denial modifiers (GA, GX, GY, or GZ) on same line

Claim Coding Example

An established patient complains of upper back pain due to gardening.

Treatment Description CPT/Modifier
Chiropractic Manipulative Treatment (CMT); spinal, three to four regions 98941 AT




Last Updated Dec 09 , 2023