HCPCS Modifier GT
Via Interactive Audio and Video Telecommunication Systems
Source: AMA CPT / CMS HCPCS Level II definitions. Maintained by the D3rx Clinical Billing Team.
What modifier GT means
Modifier GT is a legacy telehealth modifier indicating a service was furnished via an interactive audio-and-video system. For many professional claims it has been superseded by modifier 95 and telehealth place-of-service codes, but it is still required on certain claim types — notably institutional and Critical Access Hospital (Method II) telehealth billing.
When to use it
Payers or claim types that still require GT for synchronous audio-video telehealth — for example, some Medicare institutional/CAH telehealth claims.
Documentation checklist
The record should support every item below before you append modifier GT.
- That real-time, interactive audio and video were used
- The patient (originating) site and consent
- Time and/or MDM supporting the service
Do NOT use modifier GT when
- The payer now requires modifier 95 (and/or a telehealth POS) instead
- The service was audio-only
- The encounter was in person
Common denial reasons
- GT submitted where the payer has migrated to 95 + telehealth POS
- Service billed is not telehealth-eligible
- Claim type does not accept GT
How to appeal a modifier GT denial
If denied, determine whether the payer expects 95 + telehealth POS for that claim type and resubmit accordingly, attaching documentation of the real-time audio-video encounter. For institutional/CAH claims, confirm GT is still the required modifier for the bill type.
Payer notes
Medicare largely shifted professional telehealth to a telehealth POS plus modifier 95, retaining GT mainly for institutional/CAH Method II billing. Conventions vary by payer and claim type — confirm whether GT or 95 is expected.
Related & commonly confused modifiers
Where modifier GT is used
- Office/outpatient E/M (99202–99215)
- Behavioral health (90791, 90834, 90837)
- Institutional telehealth services
Got a denial citing modifier GT?
Generate the appeal with Ask D3 — free AI backed by CMS, Medicare, and major-payer data. No signup.
Medical billing disclaimer
Modifier definitions follow standard AMA CPT and CMS HCPCS Level II guidance and are for educational reference. Payer policies, billing formats, and coverage rules vary and change. Always verify the current rule with the specific payer before submitting. D3rx is not responsible for claim outcomes.