GP

Overview

Modifier GP indicates that services were delivered under an outpatient Physical Therapy (PT) plan of care. It is one of three therapy plan-of-care discipline modifiers — GP (physical therapy), GO (occupational therapy), GN (speech-language pathology) — required on every line of every outpatient therapy claim to identify which discipline ordered the plan of care.

When to use

• The service is delivered under a documented PT plan of care signed by a PT or referring physician.
• Outpatient therapy claims (hospital outpatient, CORF, private practice, SNF Part B).
• Each line of the claim corresponding to PT services.

Common mistakes

• Omitting GP on PT claim lines — Medicare denies as missing required modifier.
• Mixing GP/GO/GN on the same line — each line takes exactly one discipline modifier.

Examples

• 97110-GP — Therapeutic exercise, billed under a PT plan of care.