Locum Tenens Billing Guidelines: Essential Rules You Need to Know

Locum tenens billing guidelines under CMS can feel complex, especially for Medicare claims. From applying the Q6 modifier to managing the 60-day rule, staying compliant is critical to avoid costly denials. Let’s simplify the essential CMS rules to help you navigate locum tenens billing without any headaches.

For this post, we’re focusing on CMS’s guidelines for locum tenens. Commercial payers often follow CMS rules regarding billing practices like this. However, if you’re working with non-Medicare payers, always check your specific contract or contact provider relations for clarification. Every payer is different!

Key Takeaways:

CMS locum tenens allows substitute physicians to fill in temporarily.
The Q6 modifier must be used when billing under the regular physician’s NPI for locum tenens services.
Locum tenens services can only be billed for 60 days per year.
Locum tenens physicians must be independent and not employed by the practice.
After 60 days, you must start billing under the substitute physician’s NPI.

Now, let’s explore the details of CMS locum tenens guidelines and how to stay compliant when using this practice in your medical office.

What is Locum Tenens?

Put, locum tenens allows a substitute physician to fill in for a regular physician during an absence. This is important when a regular physician isn’t available due to things like:

Pregnancy
Vacation
Illness
Military deployment
Continuing education

The key is that the regular physician is unavailable and in good standing with Medicare or any payer they bill. The substitute physician provides services in their place, and certain billing requirements must be met.

Key Requirements for Using Locum Tenens

Here are some basic CMS locum tenens guidelines you need to follow to use a substitute physician:

1. The Regular Physician Must Be Unavailable

First, the regular physician (or practitioner) must be completely unavailable. Whether on vacation, sick, or leave, they can’t be on the premises or available to provide care.

2. Patients Must Be Regular Patients of the Absent Physician

The patients seen by the locum tenens doctor must be patients who would have been seeking care from their regular doctor if they were available. So, the locum tenens physician is acting purely as a temporary substitute.

3. Locum Tenens Must Be Paid Per Diem

CMS requires that locum tenens physicians be compensated per diem—meaning they’re paid by the day or service rather than salaried.

4. The 60-Day Rule

This is one of the big ones. You can only use locum tenens services for a maximum of 60 days per year. And yes, that includes weekends.

Example: If the locum tenens starts seeing patients on January 1st, the last day they can provide services under the regular physician’s NPI is March 1st (60 days later). After that, you’d have to start billing using the locum tenens physician’s NPI and tax ID.

Remember, the 60-day period can be consecutive or spread out over multiple stretches, but it’s cumulative—once you hit those 60 days, you’re done for the year.

What Is a Locum Tenens Physician Under Medicare?

A locum tenens provider is a temporary physician who covers for a regular physician who is absent due to illness, vacation, or other reasons.

Medicare allows the substituting physician to bill under the regular physician’s NPI (National Provider Identifier) using a modifier Q6—but only if specific rules are followed.

Here’s what Medicare requires:

✔️ The regular physician must be absent for a valid reason (e.g., vacation, illness, military duty).
✔️ The locum tenens provider must be a qualified, licensed physician.
✔️ The substitute provider must work on a temporary basis (not a permanent hire).
✔️ The locum tenens physician must not have their own practice or patient base.

Now, let’s get into the specific rules for billing and compliance.

Medicare Locum Tenens Billing Rules

1. Billing Under the Regular Physician’s NPI

Medicare allows the locum tenens doctor to bill under the regular physician’s NPI, but you must use modifier Q6 on claims.

Example:
If Dr. Smith is out on medical leave and Dr. Jones (a locum tenens physician) covers for him, all claims must be billed under Dr. Smith’s NPI with modifier Q6 attached.

2. 60-Day Rule: Maximum Coverage Period

Medicare has a strict 60-day rule for locum tenens coverage.

A locum tenens physician cannot cover for the same provider for more than 60 continuous days.
If coverage is needed beyond 60 days, a new locum tenens provider must take over, or the practice must hire a permanent replacement.

3. Payment Goes to the Regular Physician or Practice

The regular physician/practice receives payment for all services provided by the locum tenens physician.

The substitute provider cannot bill Medicare separately under their own NPI.
The practice is responsible for compensating the locum tenens doctor.

4. The Locum Tenens Provider Must Not Have a Practice in the Same Location

Medicare’s locum tenens rules do not apply if the substitute provider has an established practice in the same area.

The locum tenens doctor must be a true temporary substitute.
They cannot see their own patients while covering for another provider.

Medicare Locum Tenens Documentation Requirements

To stay Medicare-compliant, you need to maintain proper documentation when using a locum tenens physician.

What You Must Document:

📌 The reason for the regular physician’s absence.
📌 The start and end dates of the locum tenens coverage.
📌 A copy of the locum tenens physician’s credentials and license.
📌 A written agreement or contract between the locum tenens provider and the practice.
📌 Detailed patient records showing services provided by the substitute doctor.

Pro Tip: Always keep documentation readily available in case of an audit. Medicare may request proof of compliance at any time.

What Happens If You Don’t Follow Medicare Locum Tenens Rules?

❌ Claim Denials – If you forget to use modifier Q6, Medicare will reject the claim.
❌ Overpayment Demands – If Medicare finds out a locum tenens provider exceeded the 60-day limit, you may have to repay Medicare for any overbilled services.
❌ Fraud Investigations – Incorrect locum tenens billing can trigger an audit or even accusations of Medicare fraud.

Avoid the headache! Always follow Medicare’s locum tenens rules to ensure compliance and timely reimbursements.

What Is a Locum Tenens Modifier?

A locum tenens modifier is a billing code modifier used to indicate that a substitute physician has temporarily filled in for another provider.

The two most commonly used locum tenens modifiers are:

Modifier Q6: Locum Tenens Substitute Physician

Used when a temporary physician (locum tenens) replaces a regular physician for up to 60 days.
The substitute physician sees the patients under the regular provider’s NPI (National Provider Identifier).
The claim is billed as if the regular physician provided the service, with modifier Q6 attached to indicate the temporary nature.

Example Usage:
A physician goes on a 4-week medical leave, and a locum tenens doctor fills in. The medical practice bills under the regular physician’s NPI but adds modifier Q6 to the CPT code.

Modifier Q5: Reciprocal Billing Arrangement

Used when two physicians cover for each other on an occasional basis (not as part of a formal locum tenens agreement).
The substituting physician does not have to be formally contracted as locum tenens but must still work under the regular provider’s NPI.

How to Correctly Use the Locum Tenens Modifier (Q6)

Using modifier Q6 correctly ensures timely claim approvals and prevents reimbursement delays. Here’s how:

1. The Regular Physician Must Be Absent

The primary physician must be unavailable due to vacation, illness, or another reason. If they are still actively practicing, modifier Q6 cannot be used.

2. The Substitute Physician Must Be Temporary

A locum tenens physician can only work under the Q6 modifier for up to 60 consecutive days. If the temporary coverage exceeds 60 days, a different billing method must be used.

3. Bill Under the Regular Physician’s NPI

Even though the substitute physician provides the services, all claims must be submitted under the NPI of the absent provider, with modifier Q6 attached.

Example Claim Submission:

CPT Code: 99213 (Established Patient Office Visit)
Modifier: Q6
Billing NPI: Regular physician’s NPI

4. Maintain Proper Documentation

Insurance companies may request proof of locum tenens coverage, so it’s important to keep records of:

Dates the regular physician was absent
The locum tenens contract or agreement
All patient encounters conducted by the substitute physician

Billing Locum Tenens Services

Now that you’ve mastered the basics, let’s discuss billing locum tenens services. This is where people can get tripped up, but as long as you follow these rules, you’ll be good.

1. Use Modifier Q6

When billing for services provided by a locum tenens physician, you’ll bill using the regular physician’s NPI and tax ID—just as if the regular physician were seeing the patient. However, to indicate that this is a locum tenens situation, you must add modifier Q6 to the claim.

The Q6 modifier signals to CMS or any other payer that a substitute physician was filling in, and you’re still billing under the regular doctor’s credentials.

2. The Practice Cannot employ the Locum Tenens Physician

The locum tenens physician cannot already be employed by or affiliated with the practice. They must be completely independent practitioners filling in temporarily.

If your practice already employs the substitute physician, they wouldn’t be considered locum tenens. In that case, you would bill using their NPI and tax ID.

3. Stop Billing Under the Regular Physician After 60 Days

As mentioned, once the 60 days are up, you must stop billing under the regular physician’s NPI. On Day 61, if the substitute physician still sees patients, you must start billing under their NPI and tax ID number.

Why Modifier Q6 and the 60-Day Rule Matter

If you’re wondering why these rules exist, it’s all about keeping things above board and transparent. Medicare and other payers must know when a regular physician isn’t providing services; the Q6 modifier helps flag that.

The 60-day limit ensures that locum tenens physicians are only used temporarily. Once you go beyond that, you’re entering the realm of needing to credential the substitute doctor with Medicare and bill under their credentials.

What Is a Locum Tenens Modifier?

A locum tenens modifier is a billing code modifier used to indicate that a substitute physician has temporarily filled in for another provider.

The two most commonly used locum tenens modifiers are:

Modifier Q6: Locum Tenens Substitute Physician

Used when a temporary physician (locum tenens) replaces a regular physician for up to 60 days.
The substitute physician sees the patients under the regular provider’s NPI (National Provider Identifier).
The claim is billed as if the regular physician provided the service, with modifier Q6 attached to indicate the temporary nature.

Modifier Q5: Reciprocal Billing Arrangement

Used when two physicians cover for each other on an occasional basis (not as part of a formal locum tenens agreement).
The substituting physician does not have to be formally contracted as locum tenens but must still work under the regular provider’s NPI.

How to Correctly Use the Locum Tenens Modifier (Q6)

Using modifier Q6 correctly ensures timely claim approvals and prevents reimbursement delays. Here’s how:

1. The Regular Physician Must Be Absent

The primary physician must be unavailable due to vacation, illness, or another reason. If they are still actively practicing, modifier Q6 cannot be used.

2. The Substitute Physician Must Be Temporary

A locum tenens physician can only work under the Q6 modifier for up to 60 consecutive days. If the temporary coverage exceeds 60 days, a different billing method must be used.

3. Bill Under the Regular Physician’s NPI

Even though the substitute physician provides the services, all claims must be submitted under the NPI of the absent provider, with modifier Q6 attached.

Example Claim Submission:

CPT Code: 99213 (Established Patient Office Visit)
Modifier: Q6
Billing NPI: Regular physician’s NPI

4. Maintain Proper Documentation

Insurance companies may request proof of locum tenens coverage, so it’s important to keep records of:

Dates the regular physician was absent
The locum tenens contract or agreement
All patient encounters conducted by the substitute physician

What About Commercial Payers?

As mentioned, commercial payers often follow CMS locum tenens guidelines, but not always. Some payers might have different rules around how long you can use a substitute physician, how to bill them, or even whether they allow locum tenens.

Always:

Read your contract with commercial payers.
Check their provider guidelines on locum tenens billing.
Contact provider relations if you’re unsure.

Important Takeaways

To recap, the most important things to remember about CMS locum tenens guidelines are:

The regular physician must be unavailable and cannot be on-site.
Patients must seek the care they usually get from a regular physician.
You must use modifier Q6 when billing under the regular physician’s NPI.
The locum tenens must be an independent substitute—not already employed by the practice.
You can only bill for locum tenens services for a maximum of 60 days per year.

Common Billing Mistakes with Locum Tenens

Mistake 1: Forgetting the Q6 Modifier

This is a big one and happens more often than you’d think. If you’re billing for a locum tenens physician but forget to use the Q6 modifier, it’s almost guaranteed your claim will be flagged—or worse, denied. The Q6 modifier is your way of letting Medicare know that the regular doctor didn’t provide this service but by a temporary substitute.

Always double-check your billing entries to ensure the Q6 modifier is in place whenever you use locum tenens services.

How to avoid it:

Set up a reminder or a system alert in your billing software to flag any claims where locum tenens are being used. This way, you won’t forget to add the Q6 modifier.

Mistake 2: Exceeding the 60-Day Limit

Another pitfall is miscalculating the 60-day rule. Remember, the 60 days can be consecutive or non-consecutive, but they count the same. You can spread out the days, but when you hit day 61, you can no longer bill under the regular physician’s NPI using the Q6 modifier.

How to avoid it:

Keep a detailed calendar or log of when your locum tenens starts and stops seeing patients.
A tool like a shared Google Calendar could help your entire practice track those 60 days across multiple locum tenens practitioners, making sure you don’t accidentally go over.

Here’s an example of how it can be tracked:

Locum Tenens Doctor	Start Date	End Date	Total Days Used
Dr. Smith	Jan 2, 2024	Feb 28, 2024	58 days
Dr. Taylor	Mar 15, 2024	Mar 20, 2024	5 days
Dr. Johnson	Apr 5, 2024	Apr 7, 2024	3 days

This log ensures you’re not exceeding the 60-day limit, including weekends!

Mistake 3: Locum Tenens Already Affiliated with the Practice

A locum tenens physician can’t already be part of your practice. If they are already credentialed or assigned to your tax ID, you can’t bill for their services using the Q6 modifier. They must be independent, unaffiliated physicians to qualify as locum tenens under CMS rules.

How to avoid it:

Ensure the locum tenens physician hasn’t been reassigned to your practice by Medicare or another payer. You must bill under their NPI and tax ID if they are already part of your practice.

Organizing Multiple Locum Tenens Physicians

Keeping things organized can become challenging if you manage multiple locum tenens doctors in a busy practice. Here are some tips to help streamline the process:

Tip 1: Use Practice Management Software

Most billing software allows you to add special flags or alerts for locum tenens services. Use these features to track when you’ve hit the 60-day mark and ensure the Q6 modifier is applied.

Tip 2: Create a Shared Tracking Document

A simple Google Sheet or Excel document that tracks locum tenens doctors and their active days in your practice can be incredibly useful. This is particularly important if different people in your practice handle scheduling, billing, and compliance.

Here’s a template you could use:

Doctor	Start Date	End Date	Total Days Used	Q6 Modifier Applied	Notes
Dr. Smith	Jan 1, 2024	Feb 28, 2024	58 days	Yes	Consecutive days
Dr. Taylor	Mar 1, 2024	Mar 15, 2024	10 days	Yes	Weekend included
Dr. Johnson	May 1, 2024	May 10, 2024	9 days	Yes	Off and on coverage

Keeping a running tally ensures everyone in the office stays on the same page about how many days the locum tenens physician has left before hitting the 60-day limit.

Exceptions and Special Cases

A few special cases where the CMS locum tenens guidelines may need a closer look. Here’s what to keep in mind:

Emergency Situations

In emergency cases—such as a physician becoming ill unexpectedly—CMS allows locum tenens billing to begin immediately. However, the same 60-day rule still applies, even in emergencies. Make sure to document the reason for the locum tenens in the patient’s records in case of an audit.

Physician Termination

If a regular physician leaves the practice permanently (for example, retirement or resignation), you cannot use a locum tenens to fill their role beyond 60 days. After the 60-day window, the substitute physician must be credentialed under your practice and billed under their own NPI.

Military Deployment

When a physician is deployed for active military duty, the locum tenens physician can only cover for 60 days. The regular rules apply once the 60 days are up, and billing must shift to the substitute physician’s NPI.

Communication with Payers

Don’t assume every payer follows CMS guidelines regarding locum tenens. While commercial payers often model their rules after CMS, there are exceptions. Here’s how to stay on top of things:

Check Your Contracts: If you have a contract with a commercial payer, review it to see if it specifies rules about using locum tenens. Sometimes, payers have shorter or longer timeframes or may not allow locum tenens billing.
Contact Provider Relations: If you’re unsure, call the provider relations team for that payer. They can confirm whether they follow CMS locum tenens guidelines or have their own rules.

Key Credentialing Requirements for Locum Tenens Physicians

1. Active Medical License

A locum tenens physician must have a valid medical license in the state where they will be practicing.

Some states offer temporary or expedited licenses for locum tenens providers.
If the physician is working across multiple states, they may need multiple licenses.

2. DEA Registration (If Prescribing Medications)

If the locum tenens physician will be prescribing controlled substances, they must have an active DEA (Drug Enforcement Administration) registration for that state.

If they don’t have one, they may need to apply for a temporary DEA registration.

3. National Provider Identifier (NPI) Number

Every locum tenens physician must have an NPI number, which is used for billing and insurance claims.

If the physician already has an NPI, it must be active and up to date.
If billing under the facility’s group NPI, modifier Q6 (locum tenens) must be added to claims.

4. Malpractice Insurance Coverage

Most healthcare facilities require locum tenens physicians to have malpractice insurance before they can start working.

If the locum tenens agency provides coverage, verify that it meets the facility’s minimum requirements.
Some facilities require tail coverage, which extends protection beyond the end of the locum tenens assignment.

5. Background Checks & Professional References

Healthcare facilities will verify the physician’s work history, board certifications, and malpractice history.

Background checks may include criminal records, sanctions, or disciplinary actions.
Some facilities also request letters of recommendation from previous employers.

6. Hospital Privileging (If Working in a Hospital Setting)

If the locum tenens physician will be treating patients at a hospital, they must be granted hospital privileges.

Privileging verifies their ability to perform specific procedures or treatments.
The process can take several weeks, so it’s important to start early.

7. Medicare & Medicaid Enrollment (If Billing for Services)

If the locum tenens physician will be treating Medicare or Medicaid patients, they must be:

Enrolled in Medicare/Medicaid, OR
Covered under the regular physician’s billing (using modifier Q6)

Billing errors related to Medicare credentialing can result in denied claims and payment delays.

How Long Does Locum Tenens Credentialing Take?

The credentialing process can take anywhere from a few days to several weeks, depending on the:

State licensing requirements
Hospital privileging process
Insurance and Medicare enrollment timeline

To avoid delays, facilities should start the credentialing process as soon as they hire a locum tenens provider.

Why Proper Documentation Matters for Locum Tenens

When a temporary physician steps in to cover for another provider, they must meet the same licensing, credentialing, and compliance standards as permanent staff.

Without proper documentation, you could run into:

🚫 Claim rejections from Medicare and private payers
🚫 Legal and regulatory issues for non-compliance
🚫 Delays in patient care due to credentialing holdups

Having everything in order before a locum tenens provider starts working ensures seamless transitions and uninterrupted patient care.

Essential Locum Tenens Documentation Requirements

1. State Medical License

A valid medical license for the state where the locum tenens provider will be practicing is required.

Some states offer temporary or expedited licenses for locum tenens providers.
If a physician is working in multiple states, they must hold separate licenses for each state.

2. DEA Registration (If Prescribing Medications)

If the locum tenens physician will be prescribing controlled substances, they must have an active DEA (Drug Enforcement Administration) registration specific to the state of practice.

Some states require an additional state-controlled substance license.
If the provider doesn’t have a DEA registration in that state, they may need to apply for a temporary one.

3. National Provider Identifier (NPI) Number

A locum tenens provider must have an NPI number, which is used for billing and insurance claims.

The NPI must be active and linked to the provider’s credentials.
If billing under the facility’s NPI, modifier Q6 (locum tenens) must be used on claims.

4. Malpractice Insurance Coverage

Locum tenens physicians must have active malpractice insurance coverage that meets the facility’s requirements.

If a locum tenens agency provides coverage, ensure it meets minimum liability limits.
Some facilities require tail coverage to protect against claims made after the assignment ends.

5. Hospital Privileging Documents (If Working in a Hospital Setting)

If the locum tenens provider will be working in a hospital, they must obtain hospital privileges.

This process verifies their training, experience, and ability to perform procedures.
Some hospitals offer temporary or expedited privileges for locum tenens providers.

6. Proof of Board Certification (If Required by the Facility)

Many facilities require board certification in the provider’s specialty.

If not board-certified, the provider may need to show proof of training or eligibility.

7. Medicare & Medicaid Enrollment (If Billing for Services)

If a locum tenens provider is treating Medicare or Medicaid patients, they must be:

Enrolled in Medicare/Medicaid, OR
Covered under the regular physician’s billing using modifier Q6.

Failure to meet Medicare’s locum tenens billing requirements can result in denied claims.

8. Background Checks & References

Most healthcare facilities will run background checks to verify the provider’s professional history.

This may include criminal background checks, sanctions, and disciplinary actions.
Many facilities also require letters of recommendation from previous employers.

9. Provider Agreement & Contracts

The locum tenens provider must sign a formal contract outlining:

Duration of assignment
Scope of practice and responsibilities
Billing arrangements (direct vs. modifier Q6 billing)

10. Immunization & Health Records

Many facilities require proof of vaccinations and health screenings before a locum tenens provider can work.

This may include COVID-19 vaccination, TB test results, and Hepatitis B vaccinations.
Some states and facilities have specific immunization policies that must be followed.

How Long Does It Take to Complete Locum Tenens Documentation?

The documentation process can take anywhere from a few days to several weeks, depending on:

State licensing requirements
Hospital privileging process
Medicare/Medicaid enrollment timeline

To avoid delays, start gathering the necessary documents as early as possible before the locum tenens provider begins working.

Best Practices for Streamlining Locum Tenens Documentation

💡 Work with a Locum Tenens Agency – Agencies often handle licensing, malpractice insurance, and credentialing, reducing the burden on facilities.

💡 Keep Digital Copies of All Required Documents – Having licenses, DEA registration, malpractice insurance, and references ready speeds up the process.

💡 Use Expedited Credentialing Where Available – Some hospitals and payers allow for temporary or expedited privileging to fast-track provider approvals.

💡 Verify State Licensing in Advance – If the provider needs a new state medical license, begin the process early to avoid last-minute complications.

Frequently Asked Questions (FAQ) About CMS Locum Tenens Guidelines

If you still have questions about CMS locum tenens billing, you’re not alone! Here are answers to some of the most common questions about using locum tenens providers, modifier Q6, and Medicare billing rules.

What Is a Locum Tenens Physician Under Medicare?

A locum tenens physician is a temporary doctor who covers for an absent physician under Medicare rules. The locum tenens provider must not have an existing practice in the same area and must be paid per diem rather than as a salaried employee.

How Long Can a Locum Tenens Physician Cover for an Absent Physician?

Medicare allows a maximum of 60 continuous days for a locum tenens provider to bill under the regular physician’s NPI using modifier Q6. After 60 days, you must start billing under the substitute physician’s own NPI.

What Happens If a Locum Tenens Exceeds the 60-Day Limit?

If a locum tenens provider continues working beyond 60 days, they can no longer bill under the regular physician’s NPI. The practice must either:

✔ Hire a new locum tenens provider
✔ Credential the existing locum tenens under their own NPI
✔ Start billing under the substitute doctor’s NPI instead of the regular physician’s

Failing to follow this rule can lead to Medicare claim denials and potential overpayment recovery requests.

How Should I Bill for Locum Tenens Services Under Medicare?

All locum tenens claims must be submitted under the regular physician’s NPI with modifier Q6 attached.

Example Claim Submission:
- CPT Code: 99213 (Established Patient Office Visit)
- Modifier: Q6
- Billing NPI: Regular physician’s NPI

Can a Locum Tenens Physician Work for Multiple Practices?

Yes, a locum tenens doctor can work for multiple practices, but each practice must follow CMS locum tenens guidelines separately.

What Modifier Should I Use for Locum Tenens Billing?

You must use modifier Q6 when billing for a locum tenens physician under the regular provider’s NPI.

Can a Nurse Practitioner (NP) or Physician Assistant (PA) Be a Locum Tenens Provider?

No. Medicare’s locum tenens rules only apply to physicians (MDs and DOs). If a nurse practitioner or physician assistant is providing substitute coverage, different billing rules apply.

Does the Locum Tenens Physician Need to Be Credentialed with Medicare?

No, the locum tenens physician does not need their own Medicare enrollment if billing under modifier Q6 and the regular physician’s NPI.

However, if they work beyond 60 days, they must be credentialed under the practice’s tax ID and start billing under their own NPI.

Can the Locum Tenens Physicians See Their Own Patients?

No. The patients must be established patients of the absent physician. The locum tenens doctor cannot see their own patients while covering for another provider under Medicare locum tenens billing rules.

What Are the Documentation Requirements for Locum Tenens Billing?

To stay Medicare-compliant, you must keep records of:

📌 Reason for the regular physician’s absence (e.g., vacation, illness, military duty)
📌 Start and end dates of the locum tenens coverage
📌 Locum tenens provider’s credentials and state license
📌 Agreement or contract between the locum tenens provider and the practice
📌 Detailed patient records of all services provided

Always keep this documentation readily available in case of an audit.

What Happens If I Forget to Use Modifier Q6?

Forgetting modifier Q6 is a common billing mistake that leads to claim denials. If you realize the mistake after submitting a claim, you should submit a corrected claim with the correct modifier.

Can I Use Locum Tenens for a Physician Who Has Permanently Left the Practice?

No. Locum tenens is only for temporary physician absences. If a provider retires, resigns, or is terminated, the substitute physician must be credentialed under the practice and bill under their own NPI.

Do Commercial Insurance Payers Follow Medicare’s Locum Tenens Rules?

Some commercial payers follow Medicare guidelines, but others have their own locum tenens policies. Always:

✔ Check your payer contracts
✔ Review provider manuals for locum tenens billing
✔ Call provider relations for clarification

Can I Use Locum Tenens for Military Deployment?

Yes, but the 60-day rule still applies. If a physician is deployed for active military duty, they can use a locum tenens provider, but billing under the regular physician’s NPI stops after 60 days.

How Can I Track the 60-Day Limit for Locum Tenens Coverage?

To avoid exceeding the 60-day limit, keep a tracking log in a spreadsheet or practice management software.

Locum Tenens Physician	Start Date	End Date	Total Days Used
Dr. Smith	Jan 2, 2024	Feb 28, 2024	58 days
Dr. Taylor	Mar 15, 2024	Mar 20, 2024	5 days
Dr. Johnson	Apr 5, 2024	Apr 7, 2024	3 days

Keeping track ensures you don’t exceed Medicare’s locum tenens time limits.

Can I Use Locum Tenens for a Part-Time Physician?

No. Locum tenens is only for full-time physicians who are temporarily absent. If a physician works part-time, you must bill the substitute provider under their own NPI and tax ID.

Does a Locum Tenens Physician Need Their Own Malpractice Insurance?

Yes. Most facilities require locum tenens physicians to carry malpractice insurance. If the locum tenens provider is working through an agency, the agency may provide coverage.

What Happens If a Locum Tenens Provider Becomes a Permanent Hire?

If the locum tenens physician transitions to a permanent position, they must be credentialed under the practice and start billing under their own NPI.

Final Thoughts

Navigating CMS locum tenens guidelines is essential for maintaining compliance and ensuring smooth billing processes in your medical practice. By understanding and adhering to key requirements—such as using the Q6 modifier, respecting the 60-day limit, and ensuring locum tenens physicians remain independent—you can effectively utilize temporary physicians without encountering billing issues or claim denials.

Build robust tracking systems and leverage practice management software to monitor locum tenens usage to avoid common mistakes. Regularly reviewing your billing practices and staying informed about CMS and commercial payer requirements will safeguard your practice against potential pitfalls.

Implementing these guidelines ensures proper reimbursement and maintains the continuity of care your patients expect. Stay proactive, keep your billing accurate, and make the most of locum tenens solutions to support your practice efficiently.