77387 Modifier 26 in Medical Billing: How Image Guidance Is Reported in 2026
77387 modifier 26 is the professional component of image guidance for radiation treatment delivery, and in 2026 it is the only separately billable part of IGRT: the technical component is bundled into the delivery codes 77402, 77407 and 77412 in every setting.
This was the biggest change for freestanding centers this year, and some Medicare contractors were not ready for it either. Below is what the code now means and how to report it.
Where you see it
| Place | What goes there |
|---|---|
| CMS-1500 box 24D | 77387 with modifier 26, one unit per treatment date on which guidance was performed and reviewed |
| 837P electronic claim | Loop 2400, SV1: procedure 77387, modifier 26, unit count 1 |
| Medicare Physician Fee Schedule (RVU26D) | Global and 26 lines both status A, 1.09 total RVUs; TC line status B, 0.00 RVUs |
| Medicare MUE table (October 1, 2026) | 2 units per date of service |
| Remittance advice | One paid line per fraction for the physician; any 77387-TC line comes back unpaid |
Why the technical component is bundled
The CPT Editorial Panel revised 77402, 77407 and 77412 in September 2024 to “bundle imaging into the three CPT codes” and deleted 77385, 77386 and 77014. In the CY 2026 final rule CMS aligned the fee schedule with OPPS, where image guidance has long been packaged: it assigned “Procedure Status B to the technical component of CPT code 77387” because its cost “is incorporated into the costs for separately paid codes,” and the delivery codes’ practice expense RVUs “include a redistribution of the PE RVUs from the newly bundled services.”
CMS called the result a “relatively novel circumstance where the technical component of a service is bundled but the professional component is separately reported,” and set the global RVU equal to the professional RVU. Port films (77417) got the same status B treatment.
What freestanding centers lost
From 2015 through 2025 Medicare paid freestanding centers for image guidance through separate technical lines: 77014 for CT guidance, G6001 for ultrasound, G6002 for stereoscopic x-ray and G6017 for intrafraction tracking. For 2026 CMS deleted all 17 G-codes and 77014, and the technical value of guidance is now included in 77402, 77407 and 77412, priced from the relationship between OPPS APC weights rather than from the old codes’ practice expense inputs. Whether a center comes out ahead or behind depends on its mix of levels, which is why the 77407 vs 77412 decision now has more effect on payment than it did when guidance was billed separately.
Per-fraction reporting and payer per-course rules
- Medicare. One unit per date is the practical rule; the MUE is 2, which accommodates twice-daily treatment. The RVU file lists 77387 with PC/TC indicator 1, but the TC pays nothing, and Noridian’s radiation oncology page states: cannot bill 77387 with the TC modifier.
- Cigna through eviCore. “One unit of CPT 77387 with modifier-26 is allowed per date of service,” and “modifier-26 must be attached” when 77402, 77407, 77412 or the proton codes are authorized. Not with superficial treatment, brachytherapy or electronic brachytherapy, and not with SRS or SBRT, whose delivery codes include guidance (eviCore Radiation Oncology Coding Manual V1.0.2026).
- UnitedHealthcare commercial. The professional component “should be reported as 77387-26.” Image guidance is medically necessary with IMRT, with proton therapy, for re-irradiation, with implanted fiducials, and with 3D conformal therapy for a listed set of sites (breast under specific conditions, head and neck, lung, esophagus, gastric, pancreas, hepatobiliary, sarcoma, rectal and bladder boosts). Aligning to bony landmarks during palliative treatment is not (UHC policy 2026T0613L, effective March 1, 2026).
- Surface guidance. Surface guided setup and tracking is reported under the same 77387-26 line when the physician reviews it; there is no separate surface guidance code for megavoltage treatment. (Superficial and orthovoltage courses use 77439, once per course.)
The NCCI policy manual, chapter 9, keeps the rule that SRS delivery (77371 to 77373) includes guidance, and notes that 77014 and G6001 “were deleted January 1, 2026.”
Worked example: a 25-fraction head and neck course
Illustrative figures from the CMS RVU26D file at 33.4009 per RVU, national, before geographic adjustment and sequestration. 77387-26 is 1.09 RVUs, about 36.41 per unit. 77407 is 9.28 RVUs, about 309.96.
Freestanding center, single-isocenter IMRT, daily cone beam CT.
| Line | Billed by | Units | Allowed |
|---|---|---|---|
| 77407 | the center (technical) | 25 | 25 x 309.96 = 7,749.00 |
| 77387-26 | the physician | 25 | 25 x 36.41 = 910.25 |
| 77427 | the physician | 5 | 5 x 195.40 = 977.00 |
In 2025 the same course would have carried 25 technical guidance lines (77014 or a G-code) alongside the delivery lines. In 2026 there are none; the guidance line that remains is the physician’s.
Hospital outpatient department, same course. The hospital bills 77407 under OPPS. The physician bills exactly the same two lines as above: 25 units of 77387-26 and 5 units of 77427. The physician claim looks identical in both settings.
Common rejections during the transition
- Palmetto GBA denied 77387 with modifier 26 or TC for early 2026 dates of service because the code had not been loaded as a recognized code. According to the Association of Cancer Care Centers, Palmetto “provided a mass adjustment, and providers did not need to do anything,” and reported the issue resolved as of March 6, 2026 (ACCC Pulse Check). Confirm the adjustments actually posted to each account.
- Noridian Part A claims carrying 77387 under revenue code 973 stopped in the editing system with reason code 32391, “no PC/TC indicator is present for the valid HCPCS code.” Noridian “applied system updates on August 7, 2026, to allow the professional component of 77387 to process with modifier 26” (Noridian ACM Questions and Answers, September 3, 2026). Claims returned before that date can be resubmitted.
- UnitedHealthcare listed 77387 and 77439 on its bundled codes policy until January 18, 2026, which blocked physician payment; both were removed that day (ACCC, same source). CMS itself declined, in the final rule, to write “77387-26 regardless of place of service” into the Claims Processing Manual, saying it would wait for a consensus approach. Until then, the contractor and payer rules above govern.
What to do
- Post 77387-26 from the daily treatment record, one unit per treated date on which images were acquired and the physician’s review is documented. The review is what the professional component pays for.
- Remove every technical guidance line from the 2026 charge master: 77014, G6001, G6002, G6017 and 77387-TC. Keep 77417 off the claim as well (status B).
- Denials to recognize: CARC 97 with M15 or N20, or CARC 234, when a TC or global 77387 line is bundled (remove the line, nothing to appeal); CARC 4 with N519 for an invalid modifier combination; CARC 151 with N362 when units exceed 2 on a date; CARC 16 with N56 or M51 when a deleted guidance code is sent for a 2026 date (correct and resubmit); and a contractor system rejection like Palmetto’s or Noridian’s, which is a resubmission once the fix is confirmed.
- For hospital-based physicians, confirm that the treatment system export routes 77387-26 to the physician claim and the delivery code to the facility claim.
- Iridium Suite’s claim scrubber requires the 26 modifier on 77387 as the charge is entered.
Related terms
- Modifier 26 and TC
- Global, professional and technical charges
- 77407 vs 77412: choosing the delivery level
- CPT 77301: IMRT planning
- The 2026 radiation treatment delivery code changes
- Facility versus non-facility
Further reading: CY 2026 Physician Fee Schedule final rule, Radiation Oncology Treatment Delivery (Federal Register full text); CMS PFS Relative Value File RVU26D; Noridian JE Part B: Radiation Oncology; Medicare NCCI Policy Manual, Chapter 9, Radiology Services (2026).
Frequently asked
Why is 77387 billed with modifier 26 in 2026?
Because only the professional component is payable. CMS assigned status B (bundled, not separately payable) to the technical component of 77387 for 2026, to match the hospital outpatient system where imaging is packaged into the delivery codes 77402, 77407 and 77412. The physician's review of the images is reported as 77387-26 in every setting.
Can a freestanding center still bill for CT or stereoscopic image guidance?
Not as a separate technical line. 77014, G6001, G6002 and G6017 were deleted January 1, 2026, and the technical component of 77387 pays nothing. The cost of imaging is now inside the practice expense of the delivery code, which CMS priced from hospital outpatient cost data.
How many units of 77387-26 can be billed?
One per treatment date when guidance was performed and the physician reviewed it. The Medicare MUE is 2 per date of service; eviCore's manual for Cigna allows one unit of 77387 with modifier 26 per date of service. It is not reported with SRS or SBRT (77371 to 77373), with superficial therapy, or with brachytherapy.
Does Medicare pay 77387 differently with and without the 26 modifier?
No. In the 2026 RVU file the global and the professional component both carry 1.09 RVUs and the technical component carries zero. CMS said in the final rule that the two would pay the same. Commercial payers such as Cigna (eviCore) and UnitedHealthcare state 77387-26 explicitly, so appending the modifier everywhere is the safe practice.