Author(s):
Vacations, time away, or paid time off—whatever the term—benefit not only us, the taker of the time, but those around us: our coworkers and patients. To provide the best care for our patients, our wells must be as full as possible. Physicians are no exception to this rule, but their absence from the clinic can create logistical challenges. Ensuring there is appropriate coverage and keeping operations running can be stressful for ancillary staff and other physicians.
These challenges bring up a common question: How do we bill the services provided to the physician’s patients when the physician is on vacation, out of the office attending a conference, or out due to illness? The answer will depend on the setting, the services provided, and who provided the support in their absence.
The key is to ensure that staff are always aware of what is happening in the clinic. It may not always be evident who was present and/or who did the work. Additionally, there may be services only a physician can perform, especially if advanced practice providers (APPs)—such as nurse practitioners and physician assistants, also referred to as nonphysician practitioners (NPPs)—are employed by the group.
We will review these common scenarios to determine whether a service is billable, and under which name and National Provider Identifier (NPI) it should be reported—all while keeping in mind the many variables and different working arrangements that may apply. This review is meant to provide a general understanding of when to bill, when not to bill, and under which practitioner it is appropriate to bill in outpatient, hospital, and office settings.
Physician Out of Office: Hospital Setting
In the hospital setting, when the physician is out of the office, regardless of whether the physician is employed by the hospital or their own separate group, the hospital bills for the technical or hospital services under the name of the attending physician, even if that physician was not physically present and did not actually provide the professional services. Some specialties, like radiation oncology, will bill all services on the same recurring claim at the end of the month, and a single physician’s name is listed as the provider who rendered services. Typically, it is the physician to whom the patient has been assigned as their primary radiation oncologist, but it may also be another physician who is assigned in the electronic health record.
The physician billing will vary and will reflect the physician or the member of the physician group assigned to provide coverage. This is where fee-for-time compensation and incident-to billing guidelines come into play.
Fee-for-Time Compensation: Hospital and Office Setting
Fee-for-time compensation was formerly referred to as locum tenens. This naming convention changed with the 21st Century Cures Act (enacted in December 2016). Before this legislation, most people were inconsistently using the terms locum tenens and reciprocal billing arrangements.1 Consequently, the Centers for Medicare & Medicaid Services (CMS) changed the term locum tenens to fee-for-time compensation.
The Medicare Claims Processing Manual, “Chapter 1: General Billing Requirements,” addresses billing for services in cases where the physician hires someone as a substitute during their absence and pays them on a per diem or similar fee-for-time basis.2 For physician services billed under Medicare Part B, there are specific criteria that must be met:
Per the requirements listed above, there is a limit on the continuous period that a substitute physician may provide coverage: no more than 60 consecutive days. The count begins on the first day the substitute physician provides covered services to Medicare Part B patients. Days in which no services were provided, such as weekends, do count toward the 60-day total. For a new 60-day period to begin, the regular physician would need to return and provide services for at least 1 day, after which the substitute physician could begin a new 60-day period. If the substitute physician were to provide services beyond the 60-day limit that are not included in the active military duty exemption, the services provided on dates outside the window are not paid to the regular physician. Instead, services are billed under the name and NPI of the substitute physician, or the substitute physician would need to reassign payment to the group that billed for the substitute physician.
Because the substitute physician is a physician without their own practice, services are not billed under their name and NPI. Instead, services are billed under the regular physician’s name and NPI with a modifier on each code to highlight that the service was provided under a fee-for-time arrangement. Modifier Q6 (Service furnished under a fee-fortime 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) is reported on the CMS1500 claim.
If the physician is part of a group, another member of the group may provide coverage for the regular physician. In this scenario, the covering physician would bill under their own name and NPI. In a group practice such as this, the modifier to identify the fee-for-time (Q6) is not appropriate because the covering physician is part of the same physician group. Additionally, most APPs cannot provide all physician services in oncology. If they do and their state’s scope of practice allows, APPs will bill under their own name and NPI and be paid at the reduced rate, typically 85% of the assigned Medicare rate.
Documentation within the medical record must clearly identify the name and credentials of the substitute physician. The criteria for documentation do not change because a substitute physician provided coverage. The approval process, content of the documentation, and timeliness of approvals should still adhere to regulatory guidelines and internal policies.
Common compliance concerns include the delay between dictation and transcription, or situations where documentation is not available for approval until after the substitute physician’s time is complete. In these cases, the substitute physician still must approve the documentation. It would be inappropriate for the regular physician to sign off on documentation for services provided while they were absent. Cases like this may require the substitute physician to return to the office to sign off on documentation, or the services cannot be billed.
Incident-To Billing Compensation: Office Setting
Incident-to is a concept from CMS that is only applicable in the office setting. It refers to services provided to patients that are integral but ancillary to the physician’s overall services. Many times, these are services provided by ancillary staff under the direction of the physician because the physician is not expected to personally provide all services to the patient.
For example, in radiation oncology, it is the radiation therapist who will personally treat the patient with radiation. These practitioners work under the direction and supervision of the radiation oncologist, but it is the radiation therapist who sets up the patient, performs necessary imaging, and turns on the linear accelerator to deliver the radiation. The treatment delivery codes are billed under the name and NPI of the physician, even though the physician did not physically operate the treatment machine. Similar to medical oncology services, it is rare for the physician to physically administer drug regimens; this service is typically done by the nursing staff, who are working under the direction and supervision of the physician.
The key to incident-to billing is the physician’s direct supervision of the ancillary staff is required. This supervision includes all APPs/NPPs, nurses, radiation therapists, dosimetrists, and physicists. The Medicare Benefit Policy Manual, “Chapter 15: Covered Medical and Other Health Services,” addresses supervision in the office setting.3 Direct supervision in the office setting requires the physician to be present in the office suite. If a physician is out of the office on vacation, at a conference, or ill, any services provided cannot be billed under their name and NPI. Instead, another physician must be present and provide coverage via a fee-for-time compensation model, or another member of the group must cover and bill under their own name.
Remember, physician supervision and physician work are 2 different actions. Many oncology services require the physician to personally provide the work to be allowed to bill for services. Some services only require physician supervision to enable the hospital to bill, but this can vary by the service and payer guidelines. Regardless, when the physician is not present due to any planned or unplanned absence, this information must be communicated to all staff to ensure compliance with documentation and billing requirements.
To recap, physician absences are essential for maintaining clinician well-being and ensuring high-quality patient care, but they also present operational and billing challenges. It is critical that all members of a cancer program understand the appropriate mechanisms for billing services rendered during a physician’s absence, which may include fee-for-time compensation or group coverage billing, depending on the setting and circumstances. In hospital environments, technical services are billed under the attending physician, while billing for professional services depends on who actually provided care. In office settings, CMS’s incident-to guidelines apply, requiring direct physician supervision for ancillary staff and nonphysician practitioners. Accurate documentation, clear designation of substitute providers, and compliance with Medicare’s modifier requirements—such as Q6—are vital to prevent billing errors and ensure appropriate reimbursement.
Teri Bedard, BA, RT(R)(T), CPC, is executive director of Client and Corporate Resources at Revenue Cycle Coding Strategies in Des Moines, Iowa.
References
1.21st Century Cures Act. FDA. Published January 31, 2020. Accessed July 1, 2025. https://www.fda.gov/ regulatory-information/ selected-amendments-fdc-act/21st-century-cures-act
2. Medicare Claims Processing Manual, Chapter 1: General Billing Requirements. CMS. Updated June 26, 2025. Accessed July 1, 2025. https://www.cms.gov/ regulations-and-guidance/guidance/manuals/ downloads/clm104c01.pdf
3. Medicare Benefit Policy Manual, Chapter 15: Covered Medical and Other Health Services. CMS. Updated January 9, 2025. Accessed July 1, 2025. https://www. cms.gov/regulations-and-guidance/guidance/ manuals/downloads/bp102c15.pdf
At the 2026 ASCO Annual Meeting, the Louisiana Oncology Society received the ASCO Jeffrey C Ward Affiliate Advocacy Award for advancing critical advocacy priorities that have translated into meaningful legislative victories. The Iowa Oncology Society and Washington State Medical Oncology Society were also recognized for their advocacy efforts in 2025 at the meeting, receiving second place awards.
