Modifiers GT and G0: What Is Left of the Old Telehealth Modifiers

Most guidance on modifier GT says one of two things: that it is how you bill Medicare telehealth, or that it was retired years ago. Both are wrong, and the correct answer is narrower and more useful than either.

GT was eliminated for professional Medicare telehealth claims with effect from 2 January 2018. It was not eliminated everywhere: the Claims Processing Manual’s current instruction on submitting telehealth claims still requires GT on one specific kind of claim, and that instruction was last revised in 2024. Meanwhile modifier G0 — G-zero, not G-oh — is a live modifier doing real regulatory work for acute stroke telehealth, and it is routinely confused with the G-modifier liability family.

This page covers what remains. For the modifiers that carry the everyday telehealth claim, see modifier 95 versus modifier 93 and the place-of-service decision, which is where the current billing rules live.

Modifier GT: Retired for Professional Claims, Retained for One

What changed, and when

The transmittal history of Chapter 12 of the Medicare Claims Processing Manual (Publication 100-04) records the change by name: Transmittal R3817CP, issued 28 July 2017, "Elimination of the GT Modifier for Telehealth Services," change request 10152, implementation date 2 January 2018.

What replaced it was the place-of-service code. Section 190.6.1 of the same chapter, in its current revision, instructs distant-site physicians and practitioners to submit the appropriate HCPCS procedure code for covered professional telehealth services with place of service code 02 (telehealth provided other than in the patient’s home) or place of service code 10 (telehealth provided in the patient’s home). By billing POS 02 or 10 with a covered telehealth code, the distant-site practitioner certifies that the beneficiary was present at an eligible originating site. Section 190.7 states the rule from the editing side: Medicare telehealth services are billed with POS 02 and 10.

So on an ordinary Part B telehealth claim, the place-of-service code carries the certification that GT used to carry, and the modality is described by modifier 95 or 93. GT has no role.

The exception the manual still carries

Section 190.6.1 continues, immediately after the place-of-service instruction:

In situations where a CAH has elected payment Method II for CAH outpatients, and the practitioner has reassigned his/her benefits to the CAH, CAHs submit the appropriate HCPCS procedure code for the covered telehealth services with the GT modifier, and A/B MACs (A) should make payment for telehealth services provided by the physician or practitioner at 80 percent of the MPFS amount for the distant site service.

That paragraph is not a historical remnant. Section 190.6.1 carries revision 12671, issued 6 June 2024 and effective for dates of service from 1 January 2024 — six years after GT was eliminated for professional claims. GT remains the required modifier on a critical access hospital Method II institutional telehealth claim, where the practitioner has reassigned billing rights to the CAH and the claim goes to the A/B MAC (A) rather than the Part B contractor.

The reason is structural rather than historical. A CAH Method II claim is an institutional claim carrying the professional service under the hospital’s bill, and an institutional claim has no place-of-service field in which to make the certification the POS code makes on a professional claim. The modifier has to do the work instead.

A stale cross-reference worth knowing about

Chapter 12 is not internally consistent on this point, and it is better to know that than to be surprised by it. Section 190.3.6, dealing with diabetes outpatient self-management training as a telehealth service, still describes the attestation as being made "by reporting place of service (POS) 02 or the GT or GQ modifier" with the DSMT codes. That section carries an older revision than 190.6.1 and has not been conformed to the 2018 elimination.

Where two sections of the same manual point in different directions, the later-revised and more specific instruction governs, and it is Section 190.6.1 — place of service on the professional claim, GT on the CAH Method II claim. If a MAC in your jurisdiction reads the DSMT section literally, follow the MAC and document why.

Modifier G0: Acute Stroke Telehealth

Modifier G0 (the character is a zero) identifies telehealth services furnished for the purposes of diagnosis, evaluation or treatment of symptoms of an acute stroke. It is entirely unrelated to the GA, GX, GY and GZ liability modifiers despite the shared first letter — those are covered in the GX, GY and GZ guide.

What it unlocks

Section 50325 of the Bipartisan Budget Act of 2018 added paragraph (6) to section 1834(m) of the Social Security Act, providing special rules for acute stroke telehealth services furnished on or after 1 January 2019. Chapter 12, Section 190.3.7 sets out what it does:

• 1834(m)(6)(A) removes the restrictions on geographic location and on the types of eligible originating sites for acute stroke telehealth services.
• 1834(m)(6)(B) provides that they may be furnished in any hospital, critical access hospital, mobile stroke unit (as defined by the Secretary), or any other site the Secretary determines appropriate, in addition to the ordinary eligible originating sites.
• 1834(m)(6)(C) is the catch, and it is the part most often omitted: payment of an originating site facility fee is limited to acute stroke telehealth services furnished in sites that meet the usual telehealth restrictions under section 1834(m)(4)(C). The geographic restriction is lifted for the service; it is not lifted for the facility fee.

Where it goes

Effective for claims with dates of service on or after 1 January 2019, modifier G0 is valid on:

• telehealth distant site codes billed with place of service code 02, or on critical access hospital Method II claims with revenue codes 096X, 097X or 098X; and
• the telehealth originating site facility fee, billed with HCPCS code Q3014.

Note what that list implies. G0 appears on both sides of the encounter — the distant-site professional claim and the originating-site facility fee claim — and it appears on CAH Method II claims, the same channel where GT survives. On a CAH Method II acute stroke telehealth claim, both modifiers have a role.

The Third Survivor: Modifier GQ

Modifier GQ reports a service furnished via an asynchronous "store and forward" telecommunications system. Its scope is far narrower than its plain-English description suggests. Chapter 12, Section 190.6.2 limits covered store-and-forward telehealth to federal telemedicine demonstration programmes conducted in Alaska or Hawaii; by using GQ, the distant-site practitioner certifies that the asynchronous medical file was collected and transmitted to them from such a demonstration project.

Section 190.7 tells contractors to approve GQ claims only if the physician or practitioner is affiliated with a federal telemedicine demonstration conducted in Alaska or Hawaii, and permits them to require documentation of that participation before paying. Outside those two states’ demonstration programmes, GQ is not a route to billing asynchronous care.

The Decision, in One Table

Modifier	Current Medicare status	Where it goes	What it asserts
GT	Eliminated for professional telehealth claims from 2 January 2018; still required on CAH Method II claims	CAH Method II institutional telehealth claim where the practitioner reassigned benefits to the CAH	That the institutional claim carries a covered telehealth service
G0 (zero)	Live, from 1 January 2019	Distant-site code with POS 02 or CAH Method II revenue codes 096X/097X/098X; or the originating site facility fee, Q3014	That the telehealth was for diagnosis, evaluation or treatment of acute stroke symptoms
GQ	Live, but restricted	Store-and-forward telehealth within an Alaska or Hawaii federal telemedicine demonstration	That the asynchronous file came from such a demonstration project
95 / 93	Live — the everyday case	Professional telehealth claim, paired with POS 02 or 10	Audio-video (95) or audio-only (93). See the 95 vs 93 guide.

What the Record Must Show

• For a CAH Method II claim: the reassignment. The GT instruction is conditional on the practitioner having reassigned billing rights to the CAH and the CAH having elected Method II. Both are administrative facts that predate the encounter, and both should be documented and current — not assumed from how last year’s claims were paid.
• For modifier G0: that the encounter was about acute stroke symptoms. The modifier is a clinical assertion, and it unlocks the geographic and originating-site restrictions. The note should establish the presentation as suspected acute stroke at the time of the encounter, not by later diagnosis.
• For the originating site facility fee: whether the site meets the ordinary restrictions. Because 1834(m)(6)(C) preserves them for the facility fee, a site that qualifies for the service may not qualify for the fee. Record the site’s status separately from the clinical facts.
• For modifier GQ: the demonstration affiliation. Contractors may require the practitioner to document participation in the Alaska or Hawaii federal demonstration before paying. Hold that documentation.
• For everything else: the patient’s location. The POS code certifies where the beneficiary was, and the audio-only attestation under modifier 93 depends on the patient being at home. That analysis is on the 95 and 93 page.

The Misuse That Triggers Denials

1. Appending GT to a professional Medicare telehealth claim. Eliminated in 2018. The place-of-service code carries the certification now.
2. Assuming GT is dead everywhere. It is not. A CAH billing Method II telehealth without it is disregarding a 2024-revised instruction.
3. Confusing G0 with GA, GX, GY or GZ. Different family, different purpose. G0 is a clinical-category modifier for acute stroke; the others are liability modifiers.
4. Reading G0 as lifting every restriction. It lifts the geographic and originating-site-type restrictions for the service. It does not lift them for the originating site facility fee, which stays tied to the ordinary section 1834(m)(4)(C) rules.
5. Using GQ for ordinary asynchronous care. Contractors are instructed to pay GQ claims only where the practitioner is affiliated with an Alaska or Hawaii federal telemedicine demonstration.
6. Billing POS 02 or 10 on a code that is not on the telehealth list. Section 190.7 is direct: the contractor denies. No modifier fixes a code that is not a covered telehealth service.
7. Assuming a licensure problem is a modifier problem. Section 190.7 requires contractors to install edits so only properly licensed physicians and practitioners are paid for covered telehealth services, and to deny where the practitioner is not eligible to bill for them. That denial carries group code CO, CARC 185 and Medicare Summary Notice message 21.18, and no modifier changes it.

Where Jurisdiction Matters, and Where This Page Deliberately Stops

Non-Medicare payers did not follow Medicare off GT. Many state Medicaid programmes and commercial plans continued to require GT after CMS eliminated it for professional claims in 2018, and some still do. That requirement is set payer by payer and, for Medicaid, state by state; it is not derivable from the Medicare rules on this page. Check the specific payer’s current billing instructions before dropping GT from a non-Medicare claim.

This page does not state a current expiry date for Medicare telehealth flexibilities. The underlying scope of what may be furnished by telehealth at all rests on short-term statutory extensions, and the codified regulations have historically lagged the statute. The manual instructions described here — the place-of-service certification, the CAH Method II GT requirement, the acute stroke modifier, the store-and-forward restriction — are structural and stable. What is not stable is the list of covered telehealth services and the geographic and originating-site rules that sit under it. Confirm the current position for your date of service against CMS and your MAC.

Chapter 12 contains at least one unconformed cross-reference to GT, in the DSMT section, as described above. Expect to find similar residue in older sub-regulatory material and in vendor documentation, and do not treat an old reference as evidence that the modifier is current for professional claims.

Frequently Asked Questions

Is modifier GT still used for Medicare?

Not on professional telehealth claims. Transmittal R3817CP, "Elimination of the GT Modifier for Telehealth Services" (change request 10152), took effect on 2 January 2018, and distant-site practitioners now identify telehealth by place of service code 02 or 10. GT is still required on critical access hospital Method II telehealth claims where the practitioner has reassigned benefits to the CAH — an instruction carried in Chapter 12, Section 190.6.1, last revised effective 1 January 2024.

What replaced modifier GT?

The place-of-service code. POS 02 is telehealth provided other than in the patient’s home; POS 10 is telehealth provided in the patient’s home. Billing either with a covered telehealth code certifies that the beneficiary was at an eligible originating site. The modality is then described by modifier 95 (audio-video) or 93 (audio-only).

What is modifier G0 used for?

To identify telehealth services furnished for the purposes of diagnosis, evaluation or treatment of symptoms of an acute stroke, effective for dates of service on or after 1 January 2019. It is valid on distant-site telehealth codes billed with POS 02 or on CAH Method II claims with revenue codes 096X, 097X or 098X, and on the originating site facility fee billed with HCPCS Q3014.

Is modifier G0 the same as the GA, GX, GY and GZ modifiers?

No. G0 is G-zero, a telehealth modifier for acute stroke. GA, GX, GY and GZ are liability modifiers dealing with advance beneficiary notices and non-covered services.

Does modifier G0 remove the originating site facility fee restrictions?

No. Section 1834(m)(6)(C) of the Social Security Act limits payment of an originating site facility fee to acute stroke telehealth services furnished in sites that meet the usual telehealth restrictions. The geographic and site-type restrictions are lifted for the service, not for the fee.

When can modifier GQ be used?

For store-and-forward asynchronous telehealth furnished within a federal telemedicine demonstration programme conducted in Alaska or Hawaii. Contractors are instructed to approve GQ claims only where the practitioner is affiliated with such a demonstration, and may require documentation of participation.

Do commercial payers and Medicaid still want GT?

Many do. Medicare’s elimination of GT for professional claims binds Medicare, not other payers, and requirements vary by plan and by state Medicaid programme. Verify against the payer’s own billing instructions rather than assuming the Medicare position transfers.

Related CASRAI Resources

• Modifier 95 vs 93 — the modifiers that carry the everyday telehealth claim, and the place-of-service decision
• Modifiers GX, GY and GZ — the G-modifiers G0 is most often confused with
• Modifier GA: shifting liability with an ABN on file
• Incident-to billing — the other place reassignment and supervision decide whose number the claim goes out under
• Modifier KX — another modifier whose meaning is set entirely by the policy behind it
• Modifier 33 and modifier PT
• Modifiers 26 and TC — the other split between an institutional and a professional claim
• The False Claims Act in billing

Sources: CMS Medicare Claims Processing Manual, Publication 100-04, Chapter 12, Section 190.3.7 (payment for telehealth for individuals with acute stroke, Rev. 4173, effective 1 January 2019, and section 1834(m)(6) of the Social Security Act as added by section 50325 of the Bipartisan Budget Act of 2018); Section 190.6.1 (submission of telehealth claims for distant site practitioners, Rev. 12671, effective 1 January 2024, including the CAH Method II GT instruction); Section 190.6.2 (exception for store and forward); Section 190.7 (contractor editing of telehealth claims, Rev. 12671, including the CO/185/MSN 21.18 denial); and the Chapter 12 transmittal record for Transmittal R3817CP, "Elimination of the GT Modifier for Telehealth Services," issued 28 July 2017, change request 10152, implementation 2 January 2018. Noridian Healthcare Solutions modifier G0 guidance (last updated 20 August 2025) and modifier GQ guidance (last updated 14 May 2025); Noridian’s Part B modifier index carries no page for GT. The unconformed GT reference noted above is in Chapter 12, Section 190.3.6. The scope of covered Medicare telehealth services rests on statutory provisions that have been extended in short increments — this guide deliberately does not state a current expiry date; confirm the position for your date of service. CPT is a registered trademark of the American Medical Association; modifier meanings are described here in summary and the AMA’s descriptor text is not reproduced. General reference material, not coding advice for a specific claim — verify against your own MAC’s current guidance and the payer’s policy.