Adaptive Radiotherapy Billing 2026: What Is Billable

Adaptive radiotherapy billing in 2026 starts with one fact: there is no CPT code for adaptive radiotherapy, online or offline, and no payer has valued the daily re-contouring and re-planning that online adaptive platforms perform at the console. What can be billed is the ordinary set of planning, device and calculation codes, and only when the clinical record shows that anatomy changed enough to require a new imaging data set and a new plan.

That is frustrating for a department that just installed an adaptive linac or an MR-guided unit. Until a code exists, billing only what the rules allow keeps the practice safe in an audit.

The rule, in the payers’ own words

eviCore’s Radiation Oncology Coding Manual for Cigna, effective January 1, 2026, repeats the same sentence in three places (planning, calculations and devices): “Adaptive planning does not have any associated CPT codes and has not been valued by CMS. Therefore, additional units of CPT 77306, 77307, 77295, or 77301 cannot be reported when adaptive planning is performed.” The same wording blocks additional units of 77300 and of 77332, 77333, 77334 and 77338 for adaptive work.

Evolent’s January 2026 coding standards do not use the word adaptive but set the requirement for a second plan: “An IMRT plan (CPT code 77301) is billable only once during a course of therapy. In rare cases, billing a second IMRT plan during the same course of therapy may be warranted. In this scenario, planning from a new CT or MRI dataset showing a substantial change in the delineated tumor volume/volume of interest or patient anatomy is required. In addition, a statement from the physician supporting medical necessity is required and must be in the patient’s medical record.” Without a new data set, Evolent says, a second 77301 is not billable, but the new secondary calculations (77300) and new devices (77334 if compensator-based, 77338 if MLC-based) can be captured.

Medicare has no adaptive policy. The NCCI manual addresses re-planning in one line: patients receiving IMRT “occasionally require an additional treatment device at a later date due to decreased tumor volume or patient weight,” reportable with 77332 to 77334. Its MUEs cap 77301 and 77295 at one unit per date of service, 77338 at one, 77300 at ten and 77334 at ten.

Offline and online adaptive are billed differently

	Offline re-plan (traditional adaptive)	Online adaptive (daily re-plan at the console)
What happens	Patient returns for a new CT simulation because of weight loss, tumor response, or a changed immobilization fit; a new plan is built and approved	CBCT or MR acquired at each fraction, structures re-contoured, plan re-optimized and delivered in the same session
New imaging data set?	Yes, a new planning CT or MR	Yes, but it is the daily image guidance set
New plan billable?	77295 or 77301, once, when the new data set shows meaningful change and the physician documents necessity (Evolent); eviCore allows one plan per episode and no additional units for adaptive planning	No. The daily plan is adaptive planning with no code (eviCore)
Simulation?	77280 to 77290 per phase for non-IMRT; nothing for IMRT, on any date (NCCI)	No
Devices and calculations	New 77300 units per new plan; 77338 once per new IMRT plan; 77332 to 77334 when a new device is built	No additional units (eviCore)
Image guidance	77387-26 on treatment dates, one per date	77387-26 on treatment dates, one per date; the adaptive image is still the guidance image
Delivery	77402, 77407 or 77412 by the 2026 level criteria	Same; adaptation by itself does not make a fraction Level 3. Active motion management or multiple isocenters do
Management	77427 per five fractions	77427 per five fractions

Online adaptation adds nothing billable. An MR-guided prostate course with daily adaptation bills exactly what a non-adaptive IMRT course bills: the delivery code, 77387-26 and 77427, plus the single up-front plan. A commentary from Bridge Oncology (August 13, 2026) on a 17-fraction cervical cancer online adaptive study put the daily contour and plan work at roughly 16.5 minutes per fraction, none of it attached to a code.

What CCI and payer edits deny

A simulation during an IMRT course. The NCCI manual says 77301 includes simulation-aided field setting and that the edit “shall not be circumvented” by billing the simulation on a different date. The re-simulation CT for an IMRT re-plan is captured inside the new 77301, if one is justified, and nowhere else.
A second 77301 or 77295 without a new data set. Payer manuals deny it; the MUE denies two on one date.
77336 on the re-plan date. The NCCI edits block weekly physics against planning codes on the same date; the manual allows 59 or an X modifier on 77336 “because radiation planning procedures may occasionally be repeated during a course.” Use XU or XE and keep the physics note separate.
77387-26 twice in a day. One unit per date under eviCore; the MUE is 2.
77470 (special treatment procedure). Some practices use it to describe the extra adaptive work. We found no payer manual that endorses that use. Treat it as unsupported unless your payer says otherwise in writing.

Documentation that supports a re-plan

If the re-plan is going to be billed, the chart has to document it. Collect these before the claim is sent:

A physician order for re-simulation that states the clinical reason: weight loss with a quantified change, tumor response on imaging, a mask or cradle that no longer fits, a new target.
The new imaging data set, with its date, distinct from the daily guidance images.
A comparison showing the change: the old contours on the new scan, a dose-volume difference, or a photograph of the immobilization gap. Evolent asks for a “substantial change” and a “meaningful change in patient anatomy and/or delineated tumor volumes.”
The physician’s medical necessity statement for the new plan, signed and dated.
The new plan approval signed by the physician and the physicist, with the new dose constraints.
Each new device named and dated, and each new 77300 calculation tied to a field or arc.
The phase language. If the re-plan is a boost or cone-down, say so; payer manuals treat boosts differently from re-plans (eviCore allows no 77295 or 77301 for boost plans).

Worked example: a head and neck course at fraction 18

A 35-fraction IMRT head and neck course in a freestanding center. By fraction 18 the patient has lost 9 kg, the mask no longer fits, and the physician orders a new CT simulation and plan. Illustrative national amounts: 2026 RVUs times the 33.4009 conversion factor, before geographic adjustment and sequestration.

Line	Billable?	Units	Allowed (national)
77290, re-simulation	No, IMRT course	0	0.00
77301, new IMRT plan from the new CT	Yes, with the necessity statement	1	1,960.30
77338, new MLC device per IMRT plan	Yes	1	474.96
77300, one per new field or arc	Yes	7	469.98
77334, new custom mask	Yes, if a new device is actually built	1	126.26
77336, if it falls on the same date	Yes, with XU	1	92.19

Same patient, same center, but treated on an online adaptive platform that re-contoured and re-planned every one of the 35 fractions: nothing in that table is billable a second time, and the daily adaptation generates no line at all. The claim is the original plan, 35 delivery units, 35 units of 77387-26 and 7 units of 77427.

What to do now

Separate offline re-plans from online adaptation in your charge capture. Only the first can generate planning lines, and only when a new data set exists.
Build a re-plan checklist from the seven items above and attach it to every second 77301 or 77295 before release.
Never enter a simulation charge during an IMRT course, whatever the date.
Watch the MUEs: one 77301, one 77295 and one 77338 per date; ten 77300 and ten 77334.
Ask each payer in writing before billing 77470 or any other code for adaptive work; keep the answer in the payer file.
Track the policy. The CY 2027 Physician Fee Schedule proposed rule contains nothing on adaptive radiotherapy, so no change is coming on January 1, 2027; watch the CPT Editorial Panel agendas and the specialty societies for a code proposal.
Flag re-plans at entry. Iridium Suite’s CodePath audits delivery, coding and billing against the treatment plan, so a second 77301 that has no new simulation date behind it is visible before the claim is built.

Adaptive radiotherapy billing in 2026: what is billable, what is not, and how to document a re-plan