What is a Q6 Modifier in Medical Billing?

What happens if a permanent provider is unavailable for services due to an illness, vacation, military service, or another qualifying absence? Generally, in such scenarios, a substitute clinician provides services during this duration. 

However, once they render services, they must be compensated. This is where it may get tricky. How exactly does billing work in such a situation? Whose National Provider Identifier (NPI) is reported? And what’s the reimbursement rate?

This is where the modifier Q6 is used to bill services, and appending it requires accuracy and understanding. One mistake on the Q6 claim, and the result may be a denial or even an audit if similar errors are repeated. This guide covers everything you need to know about Q6. Let’s begin!

Q6 Modifier – Description

The official description of the Q6 modifier, cited by the American Academy of Professional Coders (AAPC), is:

“Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area.”

What does this mean? Q6 identifies services of an eligible substitute physician provided under a fee-for-time compensation (previously known as locum tenens) arrangement. Under certain circumstances, the modifier may also apply to substitute physical therapists, per Medicare policy. 

Understanding Q6 Usage and Application

Q6 is typically used when a physician is temporarily unavailable because of vacation, illness, military service, or other qualifying absences. To use the modifier Q6, a qualified substitute physician should provide services on the physician’s behalf.

This substitute physician provides services to patients in place of the primary service provider. The Latin term used for such a physician is “locum tenens,” which means “holding the place”, or simply, substitute.

Locum tenens arrangements are usually limited to a continuous 60-day period by Medicare for the same substitute physician. However, certain exceptions may apply under Medicare rules.  The requirements may vary if the physician is on active duty.

Appropriate Use Cases for Q6 Modifier

Billing accurately for Q6 can be challenging without a clear understanding of its strategic applications. The following are three appropriate use cases for the Q6 modifier:

Physician on Maternity Leave

Consider the case of a 36-year-old family medicine physician who works in a medically underserved area and takes 10 weeks of maternity leave. She temporarily stops seeing Medicare patients while on leave, so the practice brings in a locum tenens physician. The substitute physician provides services for up to 60 continuous days during the primary physician’s absence. 

During this period, bills are submitted under the regular physician’s NPI with the Q6 modifier to signify services provided by the substitute physician. 

Physician on Medical Leave

Say a 40-year-old cardiologist undergoes surgery, making him unable to work for six weeks. Therefore, the practice hires a locum tenens physician to handle:

• Established Medicare patients
• Manage routine cardiac care
• Conduct follow-up visits

Services provided during the primary cardiologist’s absence are billed under his NPI with the Q6 modifier, and the substitute physician is compensated per diem. 

Physician on a Vacation 

For our last example, consider the case of a 38-year-old Medicare-enrolled endocrinologist who takes a 4-week vacation to spend time with family abroad. Since he is employed by a hospital in a health professional shortage area, the facility cannot afford disruption in patient care. So, in his place, the hospital contractually hires a locum tenens endocrinologist who is paid per diem until the employed physician returns to work.

The substitute or locum tenens evaluates established Medicare patients, performs medically necessary procedures, and oversees follow-up care. Hence, his services are billed under the employed endocrinologist’s NPI, and the Q6 modifier is added to the relevant service codes.   

Accurate Usage Guidelines for Q6 Modifier

Understanding and following the guidelines for the Q6 modifier can establish the difference between a clean claim and a rejected one. However, these guidelines can often be challenging to understand. Here’s a comprehensive breakdown:

Verify Physician Eligibility

In any claim involving Q6, the practice should ensure that the substitute physician is eligible as a replacement. For this, the locum tenens physician should have a current, active, and unrestricted medical license.

The license should be valid in the state where services are being rendered. Additionally, practices should verify that the substitute physician satisfies applicable state licensing requirements. Moreover, he should meet any payer-specific participation or enrollment requirements. 

Remember, modifier Q6 cannot be appended for a provider unless all applicable licensing and payer participation requirements are met. Practices should verify that all requirements have been satisfied before billing the service. Failing to do so may result in:

• Claim denials
• Increased audit risk
• Payment recoupments

Pay the Substitute Physician as Arranged

Payment rules and structure are unique for Q6-related claims. According to the North Carolina Chiropractic Association (NCCA), the substitute physician should be compensated under a fee-for-time arrangement rather than on a fee-sharing basis. This means that either the locum tenens is paid per day (per diem) or on an hourly basis. 

Use the Correct Form Field

Accurately billing for Q6 requires filling in the correct claim form fields. The Q6 modifier should be placed in Box 24D in the CMS-1500 form. Additionally, billing teams must mention relevant HCPCS or CPT procedure codes. 

Whereas, the primary physician’s NPI should be mentioned in Box 24J. Errors in these fields may result in claim rejection, denial, or delayed payment.

Do Not Append to Non-Physician Services

As stated earlier, the Q6 modifier generally applies to substitute physician services. In limited circumstances defined by Medicare policy, it may also apply to substitute physical therapists, but not to non-physician substitutes, including:

• Nurse Practitioners (NPs)
• Certified Registered Nurse Anesthetists (CRNAs)
• Physician Assistants (PAs)

Follow the 60-Day Billing Requirement

As mentioned earlier, the Q6 modifier must be reported for a continuous substitute period of up to 60 days. If the absence is longer than that, the regular physician can only bill the initial 60 days with Q6. The remaining services will then be billed under the substitute physician’s personal NPI, given that he is a Medicare-credentialed and enrolled provider. 

Note that this 60-day billing exception only applies when a physician is called for active duty in the Armed Forces. 

Keep Complete Records

Practices must always maintain a comprehensive record of services a substitute physician provided. These services should match those on the physician’s NPI. While these records are not required for the claim, they can help during a Medicare audit. 

Final Thoughts on Q6 Modifier

The Q6 modifier reports services rendered by a substitute physician if the primary physician is unavailable because of an illness, vacation, maternity leave, or active duty. This modifier is a powerful billing tool, but requires vigilance during its use. 

If your current billing team struggles to understand modifier Q6’s requirements or billing services furnished under locum tenens arrangements, do not worry. We recommend NeuraBill’s medical billing and coding services for the handling of such claims. 

Frequently Asked Questions