PolicyRadiation Oncology billing and coding guidance
Policy CodePolicy 027
Change TypeMaterial updates to IGRT, SBRT coding and documentation
Effective Date
Next Review DateFeb 2, 2025
Key ActionDocument clinical rationale, signed prescriptions, and procedure-specific details to support claims for physics/dosimetry and special procedures.
Added documentation and billing guidance for treatment stimulation codes (G0562) and codes 77280, 77285, 77290.
Added 'Disclaimer' section.
Added related denial language including prism codes E2Q and E1N for maximum frequency exceeded.
1-3simulations typically required per course
1max CPT 77470 per course
1/8wklimit for CPT 77338
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1
CPT 77435 billed once per course
1G0339/G0340/77373 daily pay rule
2prism denial codes listed
Coverage criteria and medical necessity
Coverage criteria and billing constraints
Medical necessity guidance and billing constraints
ALL of the following
IMRT is considered reasonable and medically necessary when sparing surrounding normal tissue confers added clinical benefit.
Documentation and operational limits: verification simulations (77280) for IMRT are not billable with IMRT courses; a single simulation code (77280, 77285, or 77290) may be used for initial set-up; typical course requires 1–3 simulations and no more than one simulation may be reported on a given day.
Dosimetry and bundling: dosimetry calculations (77300) are inclusive of isodose and port plans and are not separately reportable; special dosimetry (77331) is billable only when prescribed (generally once per port/field) and not for routine IMRT or stereotactic QA.
Device and frequency constraints: only one beam‑modifying device is billable per port/field and only one unit of 77338 is billable per IMRT plan (limited to 1 unit per 8‑week period).
ANY of the following
PBT is considered reasonable when sparing surrounding normal tissue provides added clinical benefit and cannot be adequately achieved with photon‑based therapy.
Documentation and billing: proton therapy procedures require documentation to support claims and follow the same specificity and justification expectations as other complex modalities.
ALL of the following
Continuing and special medical physics consults (e.g., 77336, 77370) are allowable when clinically indicated; 77370 is allowed one time per course and requires written analysis and specific documentation.
Unlisted services (77399) should be used only when no other code adequately describes the service and not for packaged or bundled services.
ALL of the following
Limit simulation reporting to no more than one simulation per day; verification simulations for IMRT are not billable with IMRT courses.
A simulation should not be billed for daily placement of treatment fields for superficial radiation therapy.
ALL of the following
Stereotactic delivery codes (e.g., 77373, G0339, G0340, G0563) pay once per day regardless of sessions or lesions; 77435 is billed once per course (stereotactic management) and stereotactic courses are limited to a maximum of 5 fractions for SBRT/SRS treatment delivery.
ALL of the following
Denials may be issued for exceeded maximum frequency (prism denial codes such as E2Q and E1N).
Coverage and documentation criteria
Clinical and documentation criteria required to consider services reasonable/medically necessary:
ALL of the following
Treatment goal (curative, palliative, tumor control), informed consent, signed treatment plan/prescription, and documentation of treatment type and delivery details must be present in the medical record.
Treatment planning and reports (simulation, dosimetry, physics) and progress notes must be available and retained to support claims and review by Medicare upon request.
ALL of the following
A signed prescription defining goals and dose constraints for targets and critical structures is required.
A statement by the treating physician documenting the special need for IMRT versus conventional or 3‑D planning must be included.
High dose rate electronic brachytherapy, per fraction
77520
Proton treatment delivery; simple, without compensation
77522
Proton treatment delivery; simple, with compensation
77523
Proton treatment delivery; intermediate
77525
Proton treatment delivery; complex
Radiation therapy CPT/HCPCS codesmixed
77520
Proton treatment delivery; simple, without compensation
77522
Proton treatment delivery; simple, with compensation
77523
Proton treatment delivery; intermediate
77252
Proton treatment delivery; complex
77371
SRS delivery, cranial, single session (Cobalt)
77372
SRS delivery, cranial, single session (LINAC)
77373
SBRT delivery, per fraction, entire course not to exceed 5 fractions
G0339
Image-guided robotic LINAC-based SRS, complete course or first session
G0340
Image-guided robotic LINAC-based SRS, fractionated, per session
G0563
SBRT per fraction including image guidance and real-time PET-based adjustments
1–10 of 12
1/2
77338 frequency limit
Policy limitOne (1) unit of CPT 77338 is allowed per 8-week period; anything in excess requires an appeal with supporting documentation.
Per-plan capOnly 1 unit of 77338 is billable per IMRT plan regardless of the number of ports constructed for the plan.
Rationale77338 denotes MLC device(s) for IMRT; device charges are limited to prevent duplicate billing for multiple ports or constructions.
77331 frequency
Billing ruleCPT 77331 (special dosimetry) is billable only when prescribed by the treating physician and, if performed, may occur only once per port/field when supported by medical necessity.
Documentation, billing actions, and authorization
Documentation Required
Documentation and imaging billing rules
Maintain complete, signed documentation in the medical record to justify imaging and physics/dosimetry services. Documentation must include the clinical treatment goal (curative, palliative, tumor control), informed consent, prescription or treatment plan signed by the radiation oncologist, simulation and physicist/dosimetry reports, treatment device details, treatment site/isotope and number of source positions (when applicable), planned dose to each point, dates/times of procedures, and provider signatures. Records should clearly show any imaging or dosimetry results used to support billing (e.g., TLD or microdosimetry results), and any specialty physics consultation reports (CPT 77370) when performed.
Document indication and medical necessity for proton therapy (PBT) delivery codes (CPT 77520, 77522, 77523, 77252/77525) including treatment plan details, ports/isocenters, compensators, and use of custom blocks.
For special dosimetry (CPT 77331) document the treating physician's prescription, dosimetry type (e.g., TLD, microdosimetry), date/time, and results; 77331 is not billable for routine IMRT or stereotactic QA/output measurements.
To support CPT 77300 claims document the rationale for monitor unit/central axis dose calculations and limit to one calculation per port/beam angle or arc for 3D and IMRT; monitor unit calculations are bundled into brachytherapy isodose planning (77316–77318).
CPT 77370 requires a treating physician request and a customized written physics report included in the chart; reportable once per course and not reportable for routine IMRT QA.
Key definitions
Radiation therapy
DefinitionRadiation therapy uses high-energy radiation (e.g., X-rays, gamma rays, charged particles) to shrink tumors and kill cancer cells delivered as external-beam or internal (brachytherapy) treatments.
Care componentsA radiation course may include clinical treatment planning, simulation, treatment planning, physics/dosimetry, treatment devices, and treatment management.
Delivery typesDelivered externally by machines (external-beam) or internally by implanted radioactive material (brachytherapy).
Brachytherapy
DefinitionBrachytherapy is internal radiation using radioactive isotopes temporarily or permanently implanted adjacent to or within the tumor to exploit inverse square dose advantages.
FormatsBasic clinical formats include superficial, interstitial, intracavitary, and intraluminal therapy; dose can be high- or low-dose-rate.
Policy Summary
Payerpriority health
PolicyRadiation Oncology billing and coding guidance
Policy CodePolicy 027
Change TypeMaterial updates to IGRT, SBRT coding and documentation
Effective Date
Next Review DateFeb 2, 2025
Key ActionDocument clinical rationale, signed prescriptions, and procedure-specific details to support claims for physics/dosimetry and special procedures.
A signed and dated IMRT inverse plan meeting prescribed dose constraints (DMLC or SMLC or compensators) and documentation of immobilization/verification methods and secondary dose verification must be available.
Independent monitor unit (MU) checks must be completed before the patient's first treatment and fluence/distribution documentation (e.g., TPS fluence maps, EPID validation) should be maintained.
ALL of the following
Documentation must support medical necessity and frequency, including patient history/physical, functional status, and performance status (Karnofsky or ECOG).
SBRT is not considered medically necessary for patients with poor performance status (Karnofsky <40 or ECOG ≥3).
Stereotactic management (77435) may be approved for single‑fraction cranial lesions or for 2–5 fractions for other sites; courses >5 fractions will not be authorized as stereotactic management.
ALL of the following
Diagnosis codes must be coded to the highest level of specificity; unspecified diagnosis codes may be denied.
Only one type of imaging may be allowed for the same treatment site; Priority Health follows standard bundling rules and CMS NCCI guidance for imaging and IGRT billing (e.g., port images 77417 billed per 5 fractions and one imaging type per site).
ALL of the following
Stereotactic treatment delivery and management codes may require authorization; codes that pay once per day (77373, G0339, G0340, G0563) and course limits (77435) should be considered when requesting authorization.
Denials may be issued for exceeded maximum frequency (prism codes E2Q, E1N).
Not for routine QACPT 77331 is not billable for QA or output measurements associated with IMRT or stereotactic procedures.
Documentation requiredTo support CPT 77331, document the prescribing physician’s order, type of dosimetry (e.g., TLD), date/time, and results of measurements.
SBRT fraction/course limits
Maximum fractions per courseMaximum of five (5) stereotactic deliveries per course; courses greater than five (5) will not be authorized as stereotactic management.
Daily payment ruleCPT 77373 and HCPCS G0339, G0340, and G0563 pay only once per day regardless of the number of sessions or lesions treated that day.
Management code frequencyCPT 77435 (stereotactic radiation treatment management) will pay only once per course; approved when 1 fraction (cranial) or 2–5 fractions (any site) are authorized.
Port image billing frequency
Billing cadenceCPT 77417 (therapeutic radiology port image[s]) may be billed one (1) time for each 5 fractions of therapy; billed as 1 unit regardless of number of images taken.
Imaging bundlingOnly one type of imaging may be allowed for the same treatment site; Priority Health follows standard bundling rules for imaging services.
IGRT limitationIGRT precise target localization requirements are not met for superficial/orthovoltage treatments; port imaging rules apply accordingly.
Port films (CPT 77417) may be billed once per each 5 fractions as a single unit regardless of number of images; maintain image documentation and stamp dates to support fraction-level billing.
Only one type of imaging for the same treatment site is allowed for billing; IGRT requirements are not met for superficial/orthovoltage treatments and image guidance cannot be reported in those cases.
Maintain documentation when billing stereotactic management (CPT 77432, 77435) or SBRT/SRS codes showing target identification, review of CT/MRI, image guidance used, dosimetry review, and course/fraction authorization to support single-payment-per-course rules.
Support claims for brachytherapy CPT 0395T with specific procedure details (catheter placement, radiopharmaceutical or source used), dose calculations prior to loading, date/duration, and provider signature.
Electronic brachytherapy note'Electronic' brachytherapy (miniature low-kV X‑ray sources) is an emerging modality and is not subject to this Model Policy.
IMRT / PBT
IMRT descriptionIntensity Modulated Radiation Therapy (IMRT) delivers highly conformal external-beam radiation with beam intensity modulation to spare adjacent normal tissues; indicated when sparing surrounding normal tissue confers clinical benefit.
PBT descriptionProton Beam Therapy (PBT) delivers conformal external-beam radiation using positively charged particles with unique dose deposition to spare surrounding normal tissues compared to photons.
Clinical indicationBoth IMRT and PBT are used when increased conformality and normal-tissue sparing provide added clinical benefit versus conventional photon therapy.
Proton Beam Therapy (PBT)
DefinitionProton Beam Therapy (PBT) uses positively charged subatomic particles to deliver conformal external-beam radiation with reduced collateral dose to surrounding normal tissues compared with photon/X‑ray therapy.
Regulatory statusPBT is approved by the U.S. Food and Drug Administration.
DocumentationClaims for PBT (e.g., CPT 77520–77523, 77525/77252) require documentation of treatment details, ports, compensators, and rationale for complex delivery when applicable.
SBRT / SRS
SBRT definitionStereotactic Body Radiation Therapy (SBRT) delivers very high, precise doses to extracranial sites with a high degree of anatomic targeting and reproducibility to maximize tumoricidal effect while minimizing adjacent normal tissue injury.
SRS definitionStereotactic Radiosurgery (SRS) is stereotactic therapy generally delivered to intracranial targets, typically in a single session; if multiple sessions are needed, SBRT codes apply.
Course limitsStereotactic management is limited to a maximum of 5 stereotactic deliveries per course; related delivery codes (77373, G0339, G0340, G0563) pay once per day and 77435 pays once per course as appropriate.
IGRT
DefinitionImage Guided Radiation Therapy (IGRT) uses imaging technology to localize and adjust treatment delivery to account for changes in target position.
Codes/examplesExamples include guidance for localization (CPT 77387) and port images (CPT 77417) used to support IGRT workflows.
Billing constraintsPriority Health follows standard bundling rules: only one imaging type per treatment site is allowed; CPT 77417 may be billed once per each 5 fractions and is billed as one unit regardless of number of images.