Modifier Q6- Fee-for-Time Substitute Physician or Physical Therapist

Identifies qualifying Medicare services furnished by a substitute physician or physical therapist under a fee-for-time compensation arrangement when the regular provider is unavailable.

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What Is Modifier Q6?

Modifier Q6 is a HCPCS Level II modifier used for a service furnished under a fee-for-time compensation arrangement by a substitute physician or qualifying substitute physical therapist.

Under Medicare rules, a regular physician may arrange for a substitute physician to provide covered services when the regular physician is temporarily unavailable. When all requirements are satisfied, the regular physician or medical group may submit the claim and receive Medicare Part B payment as though the regular physician furnished the service.

Medicare also permits certain physical therapists to use substitute physical therapists under Q6. For PT services, this arrangement is limited to outpatient physical therapy furnished in a Health Professional Shortage Area (HPSA), Medically Underserved Area (MUA), or rural area.

Q6 is specifically associated with a fee-for-time compensation arrangement and should not be confused with ordinary reassignment, coverage within a permanently structured group practice, or other substitute-provider billing arrangements.

When to Use Modifier Q6

Regular Provider Is Unavailable: The regular physician or qualifying physical therapist is temporarily unavailable to furnish the patient's service.

Patient Seeks the Regular Provider: The Medicare beneficiary has arranged or seeks to receive services from the regular physician or physical therapist.

Fee-for-Time Compensation: The regular provider compensates the substitute on a per diem or similar fee-for-time basis.

Temporary Substitute: The substitute provides services temporarily rather than permanently replacing the regular provider under an ordinary reassignment arrangement.

60-Day Requirement: The substitute generally does not provide services to the regular provider's Medicare patients for a continuous period longer than 60 days.

Qualifying Physical Therapy: For a substitute PT, the outpatient physical therapy must be furnished in a qualifying HPSA, MUA, or rural area.

When NOT to Use Modifier Q6

No Fee-for-Time Arrangement: Do not use Q6 when the substitute is not compensated under the qualifying fee-for-time arrangement.

Permanent Replacement: Q6 is intended for temporary substitute-provider arrangements, not ordinary permanent staffing.

Routine Reassignment: Do not use Q6 simply because another enrolled practitioner in the practice performs a service under a standard Medicare reassignment arrangement.

60-Day Limit Exceeded: The substitute generally cannot continue furnishing services under Q6 beyond the permitted continuous 60-day period.

PT Outside a Qualifying Area: Substitute physical therapist services do not qualify for Q6 merely because the regular PT is absent. Medicare limits this provision to applicable outpatient PT services in HPSAs, MUAs, or rural areas.

Services Do Not Meet Medicare Requirements: Q6 does not establish coverage or medical necessity for the underlying service.

Billing Example

A Medicare patient normally receives care from a physician who will be temporarily unavailable.

The physician arranges for another physician to treat the regular physician's Medicare patients during the absence and compensates the substitute on a qualifying fee-for-time basis.

The substitute physician provides a covered service to the patient during the temporary absence.

Provided all Medicare requirements are satisfied, the regular physician bills the applicable procedure code with Modifier Q6.

Medicare processes payment as though the regular physician furnished the qualifying service. CMS states that the substitute's identification is maintained primarily to document who actually furnished the service for audit purposes rather than to determine the payment amount.

Documentation Requirements

Substitute Provider: Maintain documentation identifying the substitute physician or physical therapist who actually furnished the service.

Substitute NPI: CMS requires a record of each service furnished by the substitute along with the substitute provider's NPI, which must be available to the Medicare Administrative Contractor upon request.

Regular Provider: Clearly identify the regular physician or physical therapist for whom the substitute furnished the service.

Dates of Service: Maintain accurate dates to demonstrate compliance with the continuous-period limitation.

Compensation Arrangement: Records should support the qualifying per diem or similar fee-for-time compensation arrangement.

Service Documentation: The patient's medical record should document the service furnished and support its medical necessity.

Physical Therapy Location: When Q6 is used for substitute PT services, documentation should support that the applicable geographic requirements are satisfied.

Billing and Claim Considerations

Under Medicare's Q6 rules, the claim is generally submitted in the name of the regular physician or physical therapist, rather than treating the substitute as the billing provider for purposes of the fee-for-time arrangement.

CMS instructs medical and physical therapy groups using these arrangements to report Q6 after the procedure code in Item 24D of the CMS-1500 claim form.

The regular provider receives payment based on the service as though that provider personally furnished it, assuming all applicable Medicare requirements are met.

Q6 does not change the underlying procedure code's payment methodology and does not independently establish medical necessity.

The practice should maintain records sufficient to demonstrate that the arrangement actually satisfied Medicare's substitute-provider requirements.

The 60-Day Rule

A central Q6 requirement is Medicare's limitation on how long the substitute may furnish services.

Generally, the substitute physician or physical therapist cannot provide services to the regular provider's Medicare patients for a continuous period longer than 60 days.

CMS defines the continuous period based on the period during which the substitute furnishes covered visit services to the regular provider's Medicare patients.

A significant exception applies when a physician or physical therapist is called to active duty in the Armed Forces. In that situation, Medicare permits the fee-for-time arrangement to extend beyond the usual 60-day limitation.

Providers should carefully track dates when using Q6 rather than assuming a substitute arrangement can continue indefinitely.

Q6 Rules for Physical Therapists

Medicare's Q6 rules for physical therapists are narrower than the rules for physicians.

Section 16006 of the 21st Century Cures Act allowed a Medicare-enrolled physical therapist to use a substitute PT under a fee-for-time compensation arrangement beginning June 13, 2017.

For physical therapists, qualifying outpatient PT services must be furnished in a:

Health Professional Shortage Area (HPSA)

Medically Underserved Area (MUA)

Rural area

CMS defines a covered visit service for this purpose as outpatient physical therapy furnished in one of these qualifying areas.

The ordinary Q6 requirements—including provider unavailability, the patient's relationship with the regular therapist, fee-for-time compensation, and the 60-day limitation—also apply.

Q6 and Medical Groups

Medicare also establishes requirements for medical groups and physical therapy groups using fee-for-time substitute arrangements.

The substitute generally may not have reassigned Medicare payment rights to the group through the ordinary reassignment process for the arrangement being billed under these rules.

CMS also permits a group to temporarily replace a physician or physical therapist who has left the group for up to 60 days under qualifying circumstances.

The group must maintain records identifying the substitute and the services furnished so that the arrangement can be verified if Medicare audits the claims.

Modifier Q6 vs. Modifier Q5

Modifier Q6: Identifies qualifying substitute-provider services furnished under a fee-for-time compensation arrangement.

Modifier Q5: Identifies qualifying substitute-provider services furnished under a reciprocal billing arrangement.

The distinction is the financial and contractual arrangement between the regular provider and substitute provider.

Q6 should not be selected merely because another physician temporarily covered a patient's care. The arrangement itself must meet Medicare's fee-for-time requirements.

Modifier Q6 and Hospice Attending Physicians

CMS provides a specific Q6 rule involving hospice attending physicians.

When the designated attending physician for a hospice patient is unavailable and another physician in the group provides services related to the patient's terminal illness, CMS instructs the designated attending physician to report Q6 under the applicable circumstances.

This is a specialized application of Q6 and should not be generalized to unrelated hospice billing situations.

Common Billing Mistakes

Confusing Q6 With Q5: Q6 represents a fee-for-time compensation arrangement, while Q5 applies to qualifying reciprocal billing arrangements.

Exceeding the 60-Day Limit: Continuing to bill Q6 after the permitted continuous period can result in improper claims unless an applicable exception exists.

Using Q6 for Permanent Coverage: Q6 is not a substitute for proper Medicare enrollment and reassignment when another provider permanently joins or replaces a practitioner.

Ignoring PT Geographic Restrictions: Substitute PT services must meet the applicable HPSA, MUA, or rural-area requirement.

Missing Substitute Provider Records: Practices must maintain records identifying the substitute and the services furnished.

Assuming Q6 Establishes Coverage: The underlying service must independently satisfy Medicare coverage, coding, and medical-necessity requirements.

Common Denial Reasons

Arrangement Does Not Qualify: The substitute-provider relationship does not satisfy Medicare's fee-for-time requirements.

60-Day Requirement Not Met: The substitute furnished services beyond the permitted continuous period without an applicable exception.

Incorrect Modifier: The arrangement qualifies as reciprocal billing rather than fee-for-time compensation.

Physical Therapy Location Not Eligible: Substitute PT services were furnished outside the qualifying geographic areas.

Insufficient Documentation: Records do not adequately identify the substitute provider, dates of service, or qualifying arrangement.

Underlying Service Not Covered: The procedure itself fails applicable Medicare coverage or medical-necessity requirements.

Frequently Asked Questions

How long can a substitute provider furnish services under Modifier Q6?
Generally, a substitute physician or physical therapist may furnish covered services for no longer than a continuous 60-day period. CMS provides an exception when the regular physician or physical therapist has been called to active duty in the Armed Forces.

What is the main difference between Modifier Q5 and Modifier Q6?
Q5 applies to qualifying reciprocal billing arrangements, while Q6 applies when the substitute physician or qualifying physical therapist is compensated under a per diem or similar fee-for-time arrangement.