Decoding Billing Practices in Radiation Oncology: HOPPS vs. MPFS

​Navigating the complexities of radiation oncology billing is crucial for providers to ensure accurate payer contracting, claim submission, reimbursement, and compliance. This article delves into the distinctions between professional-only, technical-only, and global billing within the Hospital Outpatient Prospective Payment System (HOPPS) and the Medicare Physician Fee Schedule (MPFS) environments.

Medicare Payment Systems Impacting Radiation Oncology

​Radiation oncology billing is primarily influenced by two Medicare payment systems:

• ​Hospital Outpatient Prospective Payment System (HOPPS): Covers technical services and global services if physicians are employed by the hospital and services are performed in a hospital outpatient department.​
• Medicare Physician Fee Schedule (MPFS): Governs payments for physicians' professional services and freestanding centers.

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Reimbursement Structures for Radiation Therapy Services

​Understanding how reimbursement structures vary between these two models is essential for accurate billing and payment. 

HOPPS: Designed for hospital outpatient departments, HOPPS groups services into Ambulatory Payment Classifications (APCs), each with a fixed payment rate covering a bundle of related services. This system encourages efficiency as hospitals receive a set fee regardless of the actual cost of delivering care. Radiation therapy services, such as external beam treatments or brachytherapy, may be bundled in a single APC payment that covers planning, delivery, and imaging under one rate.​
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​MPFS: This schedule applies to physician practices and freestanding radiation therapy centers. Payments are based on Relative Value Units (RVUs) assigned to each service, accounting for physician work, practice expenses, and malpractice costs. Each component is billed individually under Current Procedural Terminology (CPT®) codes, resulting in more granular, fee-for-service reimbursement.

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Key Influences on Billing and Payment

• Site of Service Differential: Payments under MPFS are typically lower than HOPPS for similar services due to practice expense adjustments, reflecting the lower overhead in physician offices compared to hospital outpatient departments.
• Bundled vs. Unbundled Payments: HOPPS favors bundled payments for efficiency, while MPFS reimburses individual services, leading to more detailed billing.
• Technology-Specific Reimbursement: Advanced techniques like stereotactic radiosurgery or proton therapy may have different payment structures between the two systems, influencing where services are performed.

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Defining Professional-Only, Technical-Only, and Global Billing

Professional-Only Billing (PC): Covers the physician’s work, such as treatment planning, interpretation, and ongoing supervision of radiation therapy. It is billed with modifier 26 for codes that have both a technical and professional component, designating the professional services separate from the technical portion.

Technical-Only Billing (TC): Encompasses costs associated with radiation oncology equipment, medical physicists, radiation therapists, drugs, and supplies. It is billed using modifier –TC for codes that have both a technical and professional component to indicate that only the technical portion was performed.

​Global Billing: Includes both the professional and technical components for certain codes, meaning the same entity is responsible for providing the complete service. It is common in freestanding radiation therapy centers that own equipment and employ physicians and technical staff.

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Application in the HOPPS vs. MPFS Environments

​HOPPS Environment (Hospital Outpatient Settings): Hospitals bill for technical services under the Outpatient Prospective Payment System (OPPS), while physicians not employed by the hospital bill separately for professional services under the MPFS. Hospital-based radiation oncology centers must ensure correct separation of PC and TC billing to align with OPPS regulations.

​MPFS Environment (Freestanding Radiation Oncology Centers & Private Practices): Freestanding centers can bill for global services only if the radiation oncologists are part of the same entity that owns both the technical and professional components. If the physicians are a separate entity, the center may only bill for the technical portion. Site ​neutrality policies have affected reimbursement rates in freestanding vs hospital-based radiation oncology. 

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Key Differences in Payment Policies and Rates

Billing Type	HOPPS (Hospital OPPS)	MPFS (Freestanding)
Professional Component (PC)	Billed separately by physicians not employed by the hospital	Billed separately or as part of global billing
Technical Component (TC)	Billed by hospitals under OPPS	Billed by the freestanding center
Global Billing	Not applicable unless the physician is employed by the hospital	Common in freestanding centers
Reimbursement Model	Bundled payments for some services	RVU-based

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Implications for Radiation Oncology

CMS has proposed site-neutral payment reforms that could narrow reimbursement gaps between HOPPS and MPFS settings. The Radiation Oncology Alternative Payment Model (RO-APM) could affect reimbursement structures, shifting away from traditional fee-for-service. The current Physician Fee Schedule (PFS) has faced significant challenges, particularly in radiation oncology, where the costs of equipment, supplies, and staff have increased significantly while updates to the PFS have lagged behind [7].

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Documentation, Coding, and Compliance Considerations

Modifier Usage for Radiation Oncology Billing:
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• Modifier 26: Used for professional component billing; indicates global-to-professional component transitions.
• Modifier TC: Used for technical-only billing on specific codes.

Common Compliance Pitfalls in Radiation Oncology Billing:
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• Incorrect modifier use leading to underpayment or claim denials.
• Failure to separate PC and TC correctly in hospital settings under HOPPS.
• Billing global services when PC/TC should be billed separately, leading to compliance risks.

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Wrapping Up: Key Considerations for Billing

​Radiation oncology billing varies significantly depending on the practice setting, place of service code(s), and the applicable Medicare payment system (HOPPS vs. MPFS). Understanding the distinctions between professional-only, technical-only, and global billing is crucial for compliance and financial sustainability. Staying informed on CMS policy changes and leveraging expert billing services can help providers optimize reimbursement.

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We're Here to Help

Navigating the complexities of radiation oncology billing can be daunting, but you don't have to do it alone. At RC Billing, we specialize in providing expert billing services tailored to the unique needs of radiation oncology practices. Our team is dedicated to ensuring compliance, optimizing reimbursement, and alleviating the financial pressures associated with Medicare payment systems.

​​Visit RC Billing to learn more about how we can support your practice and help you achieve financial sustainability.

Get in Touch with Our Team Today

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References

1. Centers for Medicare & Medicaid Services. (2024). Medicare Claims Processing Manual, Chapter 13: Radiology Services and Other Diagnostic Procedures. Retrieved from https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c13.pdf
2. Centers for Medicare & Medicaid Services. (2025). Medicare NCCI Policy Manual. Retrieved from https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-policy-manual
3. Centers for Medicare & Medicaid Services. (2024). CY 2025 Medicare Hospital Outpatient Prospective Payment System and Ambulatory Surgical Center Payment System Final Rule. Retrieved from https://www.cms.gov/newsroom/fact-sheets/cy-2025-medicare-hospital-outpatient-prospective-payment-system-and-ambulatory-surgical-center-0
4. Centers for Medicare & Medicaid Services. (2024). Calendar Year (CY) 2025 Medicare Physician Fee Schedule Final Rule. Retrieved from https://www.cms.gov/newsroom/fact-sheets/calendar-year-cy-2025-medicare-physician-fee-schedule-final-rule
5. American Society for Radiation Oncology. (2025). Coding Guidance. Retrieved from https://www.astro.org/practice-support/reimbursement/coding/coding-guidance
6. Centers for Medicare & Medicaid Services. (2025). Radiation Oncology Model. Retrieved from https://www.cms.gov/priorities/innovation/innovation-models/radiation-oncology-model
7. RCCS. (2024). The Future of Radiation Oncology Payments. Retrieved from https://www.rccsinc.com/newsroom/the-future-of-radiation-oncology-payments