CPT code 77387: IGRT guidance billing, modifiers, and 2026 reimbursement

CPT code 77387 reports the image guidance used to localize the target volume during radiation treatment delivery. Since January 1, 2026, it pays as a professional-component service only. CMS gave the technical component procedure status B, so that half is bundled into the treatment delivery code and is not separately payable. The finalized 2026 work RVU is 0.68.

That change came with a rebuild of the delivery codes themselves. The CY2026 Physician Fee Schedule final rule deleted 77014, 77385, and 77386, along with the G6001 to G6017 series. Three leveled delivery codes replaced them, numbered 77402, 77407, and 77412. Any claim or charge master still carrying the deleted codes needs remapping before the next billing cycle.

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Key takeaways

CPT code 77387 reports image guidance for target volume localization during radiation treatment delivery, billed once per treatment session.

Since January 1, 2026, 77387 pays as a professional component only, because CMS gave its technical component status B.

CMS deleted 77014, 77385, and 77386 effective January 1, 2026, replacing them with delivery codes 77402, 77407, and 77412.

IMRT and VMAT now report under 77407 at Level 2, not under a dedicated IMRT delivery code.

The finalized 2026 work RVU for 77387 is 0.68.

Billing a deleted delivery code or claiming the technical component of 77387 are the two leading 2026 denial triggers.

Pabau’s claims management software tracks modifier requirements, payer rules, and session documentation so radiation oncology billing staff can reduce claim errors before submission.

77387 official code description

The American Medical Association (AMA) CPT code set gives the official descriptor for 77387. It reads: Guidance for localization of target volume for delivery of radiation treatment, includes intrafraction tracking, when performed. In practice that covers the imaging used to confirm patient positioning and target alignment immediately before or during a fraction. Clinicians know the workflow as image-guided radiation therapy, or IGRT.

What changed for CPT code 77387 in 2026

Two things changed at once, and they interact. Image guidance for every external beam modality now funnels into the single code 77387, and its technical component stopped being separately payable. Meanwhile the delivery codes it accompanies were replaced outright. A practice that fixed only one of the two ends up with rejected claims either way.

The replacement delivery codes are graded by how complex the delivery is, not by whether the plan is 3D or IMRT. Site of service no longer changes the code either. The table below shows where each level sits.

Note what moved. Motion management and image guidance are both bundled into the delivery codes now, which is why the technical side of 77387 lost separate payment. IMRT sits at Level 2, so the old habit of treating intensity modulation as automatically complex no longer holds.

These codes were deleted effective January 1, 2026, and will reject on any later date of service:

• 77014 — CT guidance for placement of radiation therapy fields. Its guidance work now sits inside 77387 and the delivery codes.
• 77385 — IMRT delivery, simple. IMRT delivery now reports under 77407, or 77412 when a Level 3 feature applies.
• 77386 — IMRT delivery, complex. Same replacement path as 77385, judged on delivery complexity rather than modulation.
• G6001 to G6017 — the HCPCS guidance and delivery series. Replaced by the three leveled CPT codes.

When is CPT code 77387 used?

CPT code 77387 applies whenever a radiation oncology practice uses imaging to localize the treatment target volume immediately before or during a session. The imaging modality does not change the code. Cone-beam CT, 2D kV or MV imaging, ultrasound localization, and electromagnetic tracking all report the same way. The imaging must be used for intrafraction target confirmation.

Per coding guidance from the American Society for Radiation Oncology (ASTRO), these clinical situations support reporting 77387:

• Stereotactic body radiation therapy requiring daily image guidance for tumor localization
• IMRT or VMAT delivery reported under 77407 where imaging confirms setup before each fraction
• Prostate treatment using cone-beam CT or ultrasound to account for daily organ motion
• Head and neck courses where patient repositioning is verified with kV imaging
• Level 3 sessions under 77412 where breath hold or gating still requires separate localization imaging
• Any session where a physician reviews and approves the localization image before delivery

CPT code 77387 is reported once per treatment session, not once per image acquired or per field treated. A patient treated with two fields in a single session generates one unit of 77387, not two.

ICD-10 diagnosis codes paired with CPT code 77387

Diagnosis coding on a radiation session claim has its own sequencing rule, and getting it backwards causes denials that look like coverage problems. The CMS ICD-10-CM code files are updated each October 1, so verify selections against the current fiscal-year tables.

Sequencing matters more than code choice here. The ICD-10-CM official guidelines put Z51.0 first when the reason for the encounter is radiation therapy, with the malignancy coded as a secondary diagnosis. Claims that lead with the tumor code and omit Z51.0 tend to come back as medical necessity denials. That label sends billing teams looking in the wrong place.

CPT code 77387 modifiers

Modifier 26 is the normal way to report CPT code 77387 in 2026, because the professional component is the only payable half. There is no longer a payable professional and technical split to divide between the facility and the physician group. The table below covers what each modifier does now.

Private payer policy diverged during the transition, and it has not fully converged. UnitedHealthcare’s revised radiation therapy guideline requires modifier 26 on 77387, while some other commercial payers denied the code when the modifier was appended. Confirm each payer’s position in writing before the date of service rather than after the first denial.

Verify requirements against your MAC’s local coverage articles as well. Record each payer’s modifier rule during eligibility verification, before the first fraction is delivered.

Medicare reimbursement for CPT code 77387

Medicare pays the professional component of CPT code 77387 under the Physician Fee Schedule, using the Resource-Based Relative Value Scale. Dollar amounts vary by locality and change each January 1. Pull locality-adjusted figures from the CMS Physician Fee Schedule lookup tool for your MAC jurisdiction.

Note: Confirm the 2026 national payment amount through the CMS PFS tool or your MAC’s fee schedule before you submit. Do not rely on third-party estimates. RVU values change annually, so recheck them each October when the proposed rule publishes.

Catching these annual updates before January 1 is what keeps a radiation oncology course billing cleanly from the first fraction. A charge master reviewed in December costs far less than a January of rejected claims.

Documentation requirements for CPT 77387

Inadequate documentation is the fastest path to a denied or recouped 77387 claim. CMS and MAC-level policies require evidence that image guidance was clinically indicated, performed, and interpreted by a physician. That is the practical test of medical billing compliance in radiation oncology. Build the habit into every session rather than retrofitting it after an audit.

• Physician order: A written order documenting the clinical indication for image guidance before the course of treatment begins
• Treatment record: Each session’s record must confirm that image guidance was performed, naming the modality used
• Interpretation, not just acquisition: 77387 pays for acquisition, fusion, review, and interpretation. The record should show all four, since only the professional work is payable now.
• Image review attestation: Dated evidence that a physician reviewed the localization images and approved positioning before delivery. A therapist note alone is insufficient.
• Matching delivery code: The session record should support the delivery level billed, whether that is 77402, 77407, or 77412
• Date and time: The imaging date and time must align with the delivery date to support the per-session unit
• Medical necessity narrative: For SBRT or complex tumor motion, add a brief justification for daily guidance rather than less frequent imaging

One documentation habit carries more weight than it used to. Because delivery level now depends on features such as motion management and isocenter count, the treatment record has to state those features explicitly. A reviewer cannot infer them from the plan name.

LCD and payer coverage policies

Medicare coverage for CPT code 77387 is governed at the MAC level. Noridian Healthcare Solutions and the other MACs apply Local Coverage Determinations that define which clinical indications support image guidance. Confirm the current LCD number and status with your own MAC, since these policies are periodically revised or superseded.

Expect some LCD and payer policy text to lag the 2026 code changes. Where a policy still names 77014 or 77385, the underlying coverage intent usually survives, but the billed code does not. Ask the payer which current code satisfies the policy instead of billing the deleted one.

A session record that lists the treating diagnosis, the delivery level, and the imaging modality gives a reviewer what they need at a glance. That is also what keeps an appeal short when a claim does get pulled.

Related CPT codes billed with 77387

CPT code 77387 never stands alone. It describes guidance for a delivery service, so the claim needs a current delivery code to give it context. The AAPC CPT code lookup is a useful cross-check before submission.

Planning and management codes were left alone by the 2026 rebuild. Only treatment delivery and image guidance changed, so 77280 through 77295, 77301, 77336, and 77427 keep working as before.

77427 and 77387 together: Radiation treatment management and image guidance cover different services and can appear on the same date. But 77427 is reported per five-fraction milestone while 77387 is reported per session. Never substitute one for the other or combine their units. The map below sets out every code’s reporting frequency across one course.

CPT 77387 vs. 77014: What replaced CT guidance

CPT 77014 was deleted effective January 1, 2026, so there is no longer a comparison to make. The two codes cannot be weighed against each other or billed on the same claim. Every image guidance service for external beam delivery now reports under 77387, whatever the modality.

The practical effect is a simpler claim with one new failure mode. Billing teams no longer manage a guidance bundling pair, but they do have to keep 77014 out of the charge master. Dates of service before January 1, 2026 still bill under the old rules. A practice working through an aging backlog needs both code sets available.

Common billing errors and how to avoid them

Denial patterns on 77387 changed shape in 2026, and most of the new ones are mapping errors rather than clinical ones. Catching them early prevents revenue leakage across a course that can run 25 to 40 sessions.

• Billing a deleted delivery code: A claim carrying 77385, 77386, or 77014 for a 2026 date of service rejects as an invalid code. Remap the charge master to 77402, 77407, and 77412.
• Claiming the technical component: Status B means 77387-TC is not separately payable. That payment already sits inside the delivery code for the session.
• Assuming IMRT is automatically Level 3: IMRT and VMAT report under 77407 unless a Level 3 feature is documented. Upcoding to 77412 without one is an audit target.
• Billing per image instead of per session: 77387 is one unit per treatment session. Two localization images in one sitting still generate a single unit.
• Missing physician interpretation: A therapist note confirming imaging was performed does not satisfy the requirement. Each session needs a dated physician attestation of review and approval.
• Reflex use of modifier 59: The old guidance bundling pair is gone with 77014. Appending 59 out of habit flags the claim without preventing anything.
• Billing 77387 with no delivery code: The code describes guidance for a delivery service. A claim without delivery context has nothing to attach to and will deny.
• Applying one modifier rule to every payer: Commercial policies split over modifier 26 during the transition. Track the rule per payer rather than per code.

Denial prevention on 77387 starts with pre-submission claim scrubbing. Reviewing the claim denial codes on each remittance tells billing teams where the cause sits. It is either the documentation, the modifier, or the code mapping. That distinction is what lets them fix the root cause instead of resubmitting.

How practice management software supports IGRT billing compliance

Image guidance billing is documentation-intensive, and the 2026 changes added a mapping burden on top. Each session generates a record that has to capture the imaging modality, the physician interpretation, the delivery level billed, and the per-session unit count. Tracking that by hand across a 30-fraction course creates audit exposure.

Practice management software like Pabau gives radiation oncology billing staff a structured workflow instead. Our claims management software keeps 77387 attached to the correct delivery code. It applies the modifier rule you recorded for that payer. It also flags a missing physician attestation before the claim reaches the payer.

Claims then route through Claim.MD, which validates each one against payer rules and NCCI edits in real time. Invalid codes and modifier errors get caught at that stage rather than after a denial. Remittance advice comes back automatically, so staff see reason codes and payment amounts without downloading 835 files from each payer portal.

Pre-submission scrubbing, clearinghouse validation, and automated remittance posting work together here. For practices running high-volume radiation courses, that shortens the distance between the treatment date and the payment date.

Streamline radiation oncology billing with Pabau

Pabau’s claims management tools help billing staff map 77387 to the right 2026 delivery code. Staff apply the modifier each payer wants, then send clean claims through Claim.MD before denial triggers hit.

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Conclusion

CPT code 77387 survived the 2026 rebuild, but the codes around it moved. The code now pays as a professional component only. Its delivery partners are 77402, 77407, and 77412. The old 77014, 77385, and 77386 are gone. Practices that have remapped their charge master and recorded each payer’s modifier rule are billing cleanly. Those that have not are seeing invalid-code rejections that look like coverage denials.

Pabau’s claims management tools give billing teams a structured way to handle 77387 across long treatment courses. That runs from delivery code mapping to real-time clearinghouse validation via Claim.MD. To see how that works for radiation oncology billing, book a demo with the Pabau team.

Continue your research

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