Locum Tenens Billing​ Guidelines 2026

Did you know that according to the American Association of Hospitals, vacancies, burnout, and administrative burden are the top concerns for healthcare leaders? Because of these factors, a physician may step away temporarily for a:

• Vacation
• Illness
• Continuing education
• Parental leave

In such cases, a substitute provider is brought in to maintain operations and patient care. This substitute physician is known as a locum tenens physician, which means “to hold place” in Latin. However, locum tenens billing is not as straightforward as it might seem at first. 

Locum billing involves submitting claims for services rendered by a temporary substitute physician under the absent physician’s National Provider Identifier (NPI) number. This does not require enrolling the substitute as a new provider. 

Such a situation can make billing for locum tenens physicians​ confusing, resulting in errors by staff. If your practice values accurate claim submission, you must understand the locum tenens billing guidelines​ and how to implement them.

CMS Billing Guidelines for Locum Tenens

The Centers for Medicare & Medicaid Services (CMS) has established specific billing rules for locum tenens arrangements. These rules are designed to prevent misuse and ensure Medicare reimburses claims correctly. 

CMS recognizes locum tenens billing under the fee-for-time compensation provisions described in the Medicare Claims Processing Manual.

Through locum tenens billing, a substitute physician (not an active employee of a regular physician) can provide services to a regular physician’s patients due to the regular physician’s unavailability.

Claims are submitted under the regular physician’s NPI, with the appropriate modifier, rather than under the substitute physician’s NPI.

Conditions Where Locum Tenens Billing is Permissible

Practices or facilities may use locum tenens billing if and when a regular physician is temporarily absent due to:

• Continuing medical education
• Vacation
• Illness
• Pregnancy
• Another similar reason

Secondly, for Medicare fee-for-service compensation arrangements, the substitute physician is typically not a regular employee of the practice and is compensated on a fee-for-time basis.

Q5 and Reciprocal Billing Arrangements

Reciprocal billing arrangements are similar to locum tenens billing, but they are not the same. They use the Q5 modifier instead of the modifier used for locum tenens.

Reciprocal billing is usually used when:

• Two physicians work in the same practice or have the same specialty
• They occasionally cover for each other when one is unavailable

Important: Locum tenens billing and reciprocal billing have different billing rules. Before submitting a claim, make sure you know which arrangement applies so you use the correct modifier and follow the right requirements.

The 60-Day Rule

The 60-day rule is a crucial CMS restriction that must be followed during locum tenens billing. According to this rule:

A substitute physician generally may not furnish services for the same absent physician beyond the Medicare 60-day limit. The following rules apply to it:

• Practices should start counting the first day a substitute physician examines or sees a patient. 
• The date of the regular physician’s absence shouldn’t be the starting point. 
• The 60-day count should include the weekends. 
• The period begins again if the regular physician returns for even a day. 
• If the duration resets, facilities or practices may use a different or the same locum again.

However, for physicians on active duty in the armed forces, the 60-day limit may not always be applicable.

Locum Tenens Billing Modifier

The HCPCS modifier Q6 is used to identify services furnished by a substitute physician under Medicare’s fee-for-time compensation (locum tenens) arrangement. Typically, the modifier is appended to the CPT or HCPCS procedure code on the claim. 

The claim is submitted under the regular physician’s name and NPI, with modifier Q6 appended when Medicare’s requirements are met. If a locum tenens claim does not include modifier Q6 when required, it may result in:

• Payment delays
• Claim denials
• Compliance issues

However, there is one exception. The Q6 modifier may not be used for postoperative services provided within a global surgical period.

Important Billing Insight: Billing requirements for nurse practitioners (NPs), physician assistants (PAs), and other non-physician practitioners differ from physician locum tenens arrangements and should be verified before billing

How to Bill for a Locum Tenens Physician?

Billing for locum tenens physicians​ is essential to ensure Medicare compliance when physicians are substituted in particular conditions. Billing teams can use the following checkpoints when submitting locum tenens claims.

Verify the Eligibility of the Locum Tenens Arrangement

Many new billers assume every temporary physician arrangement qualifies for locum tenens billing. However, that is not always the case. The first step is to verify that the arrangement meets Medicare’s locum tenens requirements.

For locum tenens billing, the regular physician must genuinely be temporarily unavailable. Additionally, the substitute physician cannot function as a permanent member of the practice under a locum tenens arrangement.

If the arrangement becomes long-term or effectively permanent, the substitute physician generally must be credentialed and enrolled according to the payer’s enrollment requirements.

Review Eligibility Requirements

A substitute physician should typically not be an employee or partner of the practice. The substitute physician should have their own NPI. However, qualifying Medicare locum tenens claims are submitted under the regular physician’s NPI with modifier Q6.

Some commercial payers have their own enrollment requirements. Therefore, always verify payer-specific billing rules before the assignment begins.

Maintain Proper Documentation and Records

Every locum tenens arrangement should be supported by complete and accurate documentation. CMS may request documentation verifying:

• Dates of service
• Unavailability of the regular physician
• Identity of the substitute physician

The practice should also maintain a written agreement with the locum tenens physician. Also, an internal log must be maintained to track the 60-day coverage period. 

Common Billing Mistakes for Locum Tenens

Locum tenens billing is a practical option for uninterrupted patient care and compliance. However, this type of billing also has challenges that billing professionals may face. These may include:

Exceeding the CMS 60-Day Limit

Medicare’s reciprocal billing and fee-for-time compensation rules dictate that a locum tenens physician cannot provide services for more than 60 uninterrupted days for the same physician absent or unavailable.

The 60-day period ends if the regular physician returns to duty within this period. If the team continues to bill the absent physician after the allowable period, it may be considered an overpayment, obligating repayment.

Missing or Incorrect Q6 Modifier

The Q6 modifier is reported when Medicare’s locum tenens billing requirements are met. If the claim does not include the modifier or includes an incorrect one, it may lead to:

• Payment delays
• Claim denials
• Audit findings

Additionally, the billing staff should ensure that the Q6 modifier is reported only when Medicare’s locum tenens requirements are fulfilled.

Missing Payer-Specific Billing Policies

Not all payers process locum tenens the same. For instance, commercial payers might not follow Medicare’s locum tenens rules. 

Some payers may require credentialed physicians, whereas others might not consider reciprocal billing valid at all.

Therefore, verifying specific requirements is an effective way to avoid claim denials. Assuming all payers follow Medicare can lead to errors.

Submitting Inaccurate or Incomplete Documentation

Poor documentation is a frequent trigger of claim denial and violation of locum tenens guidelines. Therefore, medical billing teams should ensure that the documentation clearly identifies:

• The regular physician who was replaced
• The reason for the absence of the regular physician
• The duration of the coverage period
• The substitute physician’s identity
• Fee-for-time payment arrangement demonstrated with documentation

If your claims are backed by incomplete or incorrect documentation, it may cause claim delays, denials, or an extensive audit against your practice.

Billing Under the Wrong NPI

For locum tenens billing, Medicare generally requires billing under the regular physician’s NPI with modifier Q6 when locum tenens requirements are met.

If billing teams use an incorrect NPI, they may be at risk of claim rejections and inaccurate payments.

Failure to Meet Medicare Eligibility Requirements

Not every substitute physician qualifies as a locum tenens physician. Instead, Medicare has specific requirements that must be met before substitute physician services are billed under the locum tenens billing provisions.

For instance, an eligible physician should be paid on a per diem or fee-for-time basis. Secondly, the regular physician must be unavailable because of circumstances such as: 

• Vacation
• Military service
• Illness
• Continuing medical education

If billing professionals misapply this locum tenens billing guideline, they may face compliance risk, claim denials, or overpayment liability.

Failing to Track the 60-Day Rule

Several practices use legacy systems or manual spreadsheets/ calendars for tracking substitute physicians. It may seem like a harmless practice, but it can increase the risk of billing the provided services beyond the allowed coverage period.

Conversely, automated compliance alerts and tracking systems are a better monitoring alternative. Ideally, practices and facilities should track the activities at the start and end of locum tenens arrangements.

Incorrect Diagnosis or CPT Coding

Locum tenens guidelines impact billing but not the service coding. Therefore, the diagnoses and procedural coding requirements typically remain unchanged. 

Therefore, the services performed should be reported on the claims with their corresponding HCPCS, CPT, and ICD-10-CM codes.

Internal Compliance Audit Errors

Periodic reviews of locum tenens billing are necessary to maintain compliance and billing accuracy, but some practices may overlook this step. Billing staff can identify various errors with regular audits, such as:

• Missing Q6 modifiers
• Incorrect NPIs
• Documentation deficiencies
• Exceeding the coverage period

Best Practices for CMS Compliance

CMS compliance is essential for accurate locum tenens billing, but it is also one of the biggest challenges practices may face. The following best practices can help maintain CMS compliance for locum tenens billing:

• Complete credentialing and exclusion screening for the substitute physician before they begin providing services or before any claims are submitted, as required by the payer.
• Report the appropriate billing modifier according to each payer’s billing guidelines.
• Track the Medicare 60-day coverage period beginning with the substitute physician’s first day of furnishing services to avoid exceeding the allowable limit.
• Verify payer-specific billing requirements before claim filing. Commercial insurers and state Medicaid programs may not follow Medicare’s rules for locum tenens billing.
• Maintain clear documentation of service dates, coverage arrangements, and any supporting records required for billing.
• Routinely verify modifier accuracy, documentation completeness, and NPI usage via audits. 

Wrapping It Up

Locum tenens billing involves several important elements, such as the

• 60-day rule
• Q6 modifier
• Documentation standards
• Payer-specific variations

Before any practice hires a substitute in the absence of a regular physician, they must comply with the requirements discussed in this article for 2026. Unfortunately, these requirements are complex, and even experienced billing teams can miss a step. 

However, third-party companies such as MediBillMD provide expert medical billing services to ensure you are audit-ready year-round.