How radiation oncology billers, coders, and clinic managers build a clean brachytherapy claim, from applicator insertion to the last fraction, under current CMS, NCCI, ASTRO, and Noridian JF rules.
Brachytherapy claims rarely fail because a coder picked a code from the wrong chapter. They fail because the claim bills a service that Medicare already counts as part of another code. Basic dosimetry gets billed on top of a code that includes it. Weekly management gets billed during an implant. Source handling shows up on a high dose rate (HDR) line. A third HDR fraction on the same day pushes past the unit limit. Hospital seeds go out without the per-source C-code lines. Each one of these is a bundling or unit problem, not a lookup problem.
The thesis of this post is simple. A brachytherapy course is a chain of separate steps, and Medicare packages more of those steps than most charge masters assume. If your team maps each step to the rule that controls it (the code descriptor, the National Correct Coding Initiative (NCCI) policy, the Medically Unlikely Edit (MUE), the global period, and the payment system), the claim holds up. If the team bills every step that happened, the claim gets cut.
This post covers radiation oncology brachytherapy only. It does not repeat our September 28, 2026 post on leveled external beam delivery (77402/77407/77412) and image guidance. Where external beam radiation therapy (EBRT) appears here, it is only to show how the two modalities interact on one course.
The low dose rate and high dose rate thresholds and the interstitial, intracavitary, and surface categories come from ASTRO’s brachytherapy model policy. That document also explains that LDR complexity is counted by sources and HDR complexity is counted by channels. The CPT codes follow that logic.
The 2026 change that touches brachytherapy is narrow. Category III code 0394T (HDR electronic brachytherapy, skin surface) is gone. It does not appear on the 2026 PFS relative value file or the October 2026 OPPS Addendum B. ASTRO’s coding FAQ confirms that 0394T cannot be reported in 2026 and that skin eBT now goes to the new surface radiation codes, 77436 and 77437. The CY 2026 PFS final rule describes 77437 as including electronic brachytherapy. Our September 28 post covered that surface radiation family in depth, so we will not repeat it here. For a Washington skin case, though, remember one line from Noridian LCD L40176: electronic brachytherapy for nonmelanoma skin cancer “is not considered reasonable and necessary at this time.”
0395T (HDR electronic brachytherapy, interstitial or intracavitary, per fraction) remains. It is contractor-priced on the PFS (status C) and sits in OPPS APC 5624 with status indicator S. ASTRO notes that 0395T includes basic dosimetry, so 77300 is not added. Per CPT instruction as summarized by ASTRO, planning, isodose, device, management, and radionuclide brachytherapy codes are not reported in addition to 0395T. The MUE is 2 per day.
The radionuclide brachytherapy family (77750, 77761–77763, 77767–77768, 77770–77772, 77778, 77789, 77790, and unlisted 77799) is active on both the 2026 PFS file and the October 2026 OPPS file. The brachytherapy isodose plans 77316–77318 are also active. The rest of this post is about getting those codes right.
Think of a brachytherapy course as six questions. Each answer points to a different code family and a different bundling rule.
If your charge capture template asks these six questions in this order, most of the errors in this post never reach the claim.
These are professional-only codes on the PFS (PC/TC indicator 2). Under OPPS, 77263 carries status indicator B, which means the hospital is not paid for 77263 on the outpatient claim. ASTRO’s FAQ addresses a common split-care case: when one physician supervises EBRT at one facility and a physician in another practice performs the brachytherapy, both may report 77263.
Brachytherapy often needs imaging of the applicator with dummy sources in place. NCCI gives one specific rule for partial breast HDR, which may be delivered twice a day. The first simulation of the course may be reported as complex (77290). Later simulations during that course are reported as 77280.
The plan level follows the number of sources (LDR) or channels (HDR). Simple covers 1–4 sources or one channel. Intermediate covers 5–10 sources or 2–12 channels. Complex covers more than 10 sources or more than 12 channels. All three include basic dosimetry. Three rules matter here:
When a patient also receives EBRT in the same course, ASTRO’s FAQ says to report the external beam plan (77295, 77301, 77306, or 77307) and, for the brachytherapy portion, typically 77316–77318. For the 3-D plan, note that Noridian JF’s radiation oncology page says 77295 is billed only once per treatment course, and the MUE for 77295 is 1 per day. If your physicians build a new 3-D brachytherapy plan for each fraction, get written payer direction before billing more than one.
NCCI policy says 77300 is integral to some clinical brachytherapy codes, naming 77767–77772 and 77778 as examples. It “shall not be reported with these clinical brachytherapy procedure codes.” The same rule applies to 0395T per ASTRO. Remove 77300 from every HDR charge template.
77336 is a weekly code. NCCI says brachytherapy codes 77750–77790 include it, so it “should not in general be reported separately with brachytherapy services.” NCCI names two exceptions:
NCCI also blocks 77336 with planning codes 77261–77295, 77301–77318, and 77332–77334 on the same date. Modifier 59 or XE, XP, XS, or XU may be appended to 77336 only when a planning service is truly repeated during treatment on the same date.
Both 77336 and 77370 are technical-only codes (PC/TC indicator 3), so modifiers 26 and TC are never used with them. CMS’s Claims Processing Manual says they are payable in settings where technical components are payable. The MUE for each is 1 per day.
The insertion is a separate surgical service. It is reported with a code from the anatomic section, not the 77xxx brachytherapy codes. Common examples, all confirmed active on the 2026 PFS file:
| Code | What it describes (plain language) | PFS global | OPPS status |
|---|---|---|---|
| 57155 | Uterine tandem and/or vaginal ovoids for clinical brachytherapy | 000 | J1 |
| 57156 | Vaginal radiation afterloading apparatus (cylinder) | 000 | T |
| 58346 | Heyman capsules for clinical brachytherapy | 090 | J1 |
| 55920 | Needles or catheters into pelvic organs or genitalia (not prostate) | 000 | J1 |
| 55875 | Transperineal needles or catheters into the prostate | 090 | J1 |
| 19296 | Expandable breast afterloading catheter, on a date separate from the partial mastectomy | 000 | J1 |
| 19297 | Expandable breast afterloading catheter, concurrent with partial mastectomy (add-on) | ZZZ | N |
| 19298 | Multiple tube-and-button breast brachytherapy catheters | 000 | J1 |
| 20555 | Needles or catheters into muscle or soft tissue | 000 | J1 |
| 41019 | Needles, catheters, or devices into the head and neck | 000 | J1 |
| 31643 | Bronchoscopy with catheter placement for intracavitary radioelement application | 000 | J1 |
| 76965 | Ultrasound guidance for interstitial radioelement application | XXX | N |
| 49411 | Interstitial device placement for radiation guidance (for example, gyn fiducials) | 000 | S |
Four points matter for billing teams.
Global periods follow the insertion code. 55875 and 58346 carry a 90-day global on the PFS, which means related post-procedure visits by the same physician are already paid. The 000-global codes include same-day pre- and post-procedure work.
Hospital C-APC packaging. Under OPPS, status indicator J1 means the insertion is the primary service of a comprehensive APC, and other covered Part B services on that claim are packaged into it, except for listed exclusions. Brachytherapy sources (status indicator U) are one of those exclusions, according to CMS’s Claims Processing Manual. ASTRO reports that tandem-and-ovoid insertions (57155) delivered over multiple encounters can be reported per encounter.
Fiducials. ASTRO’s FAQ supports 49411 for gynecologic fiducial placement (for example, at the vaginal cuff), reported once regardless of how many devices are placed.
The 77778 intraoperative trap. NCCI states that 77778 requires the radiation source to be applied interstitially. A radiation oncologist does not report 77778 for intraoperative work while another physician places catheters, unless the radiation oncologist also applies the source at that same encounter. That intraoperative work may be reportable with a non-brachytherapy code. If the source is applied later, after surgery, in a different room, the radiation oncologist may report HDR codes 77770–77772 for the source application.
All five are split-billable codes on the PFS (PC/TC indicator 1), so a freestanding center bills globally and a hospital-based physician bills with modifier 26. They have no global period (XXX). Under OPPS, 77770–77772 sit in APC 5624 (October 2026 national unadjusted rate $711.56), and 77767–77768 sit in APC 5622 ($394.05), all with status indicator S.
Count channels from the treatment record, not the applicator name. A single-channel cylinder is 77770. An applicator set treated through 2 to 12 channels is 77771. An implant treated through more than 12 channels is 77772. The same applicator type can land in different tiers, so document the actual number of channels treated for each fraction.
Two per day, maximum. The Q4 2026 MUE for 77767, 77768, 77770, 77771, and 77772 is 2 units per day, with a clinical date-of-service edit. That supports twice-daily partial breast HDR, which NCCI recognizes. It does not support three. Document both session times and the break between them.
No 77300, no 77790. NCCI says 77300 is integral to 77767–77772. Separately, NCCI says 77790 (supervision, handling, and loading of the radiation source) is not separately reportable with 77770–77772 or 77778, because those procedures include that work. Hospitals have one extra option under CMS’s Claims Processing Manual: report 77790 charges separately or fold them into the application code charge. Under OPPS, 77790 has status indicator N (packaged), so either way it does not generate separate payment.
No weekly management. 77427 and 77431 are included in brachytherapy. Bill them only for concurrent external beam fractions.
E/M is the HDR exception. NCCI generally bars E/M after the initial decision visit with radiation oncology services. It makes one exception: E/M services beyond the initial visit may be reported with 77770–77772 if they are “significant, separate, and distinct from radiation treatment management services.” That is a high bar. A routine pre-fraction check does not meet it. A new, separately documented problem might meet it. If an NCCI edit applies, use the NCCI-associated modifier your payer requires and keep the separate note in the chart.
HDR sources in the hospital. HDR iridium-192 is reported with C1717 (HDR Ir-192). It has status indicator U, APC 2646, and an October 2026 national unadjusted rate of $357.49. The MUE is 10 per day.
Respect the 90-day global. ASTRO’s model policy states that follow-up visits for 90 days after treatment are not separately payable for 77750 and 77761–77763. That matches the 090 global on the 2026 PFS file. 77778 and 77789 have a 000 global, so the 90-day restriction does not apply to them.
One per day for most LDR codes. The MUE is 1 for 77750, 77761, 77762, 77763, and 77778. It is 2 for 77789.
Do not add 77790 to 77778. The 77778 descriptor includes source handling, and NCCI bars 77790 with it.
No 77300 with 77778. NCCI names 77778 among the codes where basic dosimetry is integral.
Use ultrasound guidance correctly. 76965 (ultrasound guidance for interstitial radioelement application) is split-billable on the PFS. Under OPPS, it is packaged (status indicator N).
CMS pays hospital brachytherapy sources separately from the procedure that places them. The CY 2026 OPPS final rule continues source-specific APC payment, generally based on geometric mean unit costs from CY 2024 claims. CMS’s Claims Processing Manual adds the billing mechanics:
The October 2026 Addendum B lists source codes such as C2638 (stranded iodine-125, $35.26 per source), C2639 (non-stranded iodine-125, $36.64), C2640 (stranded palladium-103, $88.26), C2641 (non-stranded palladium-103, $64.48), C2642 (stranded cesium-131, $119.11), and C2643 (non-stranded cesium-131, $99.80). Those dollar amounts are national unadjusted rates, and each of those codes has status indicator U. For a new source without its own code, CMS pays C2698 (stranded, not otherwise specified) and C2699 (non-stranded, not otherwise specified) at the lowest stranded or non-stranded per-source rate: $35.26 and $36.64. The Q4 2026 MUE is 150 per day for C2638–C2641 and 120 for C2642–C2643. A larger implant needs documentation and may need a payer conversation before the claim goes out.
On the 2026 PFS file, Q3001 (radioelements for brachytherapy, any type, each) is contractor-priced (status C). Under OPPS, Q3001 has status indicator B, which means it is not recognized on hospital outpatient bill types. Hospitals use the source-specific C-codes instead. For freestanding claims, check how Noridian JF prices Q3001 and what invoice documentation it expects before the first implant of the year.
This is the simplest rule in the course, and it is still missed. NCCI states that brachytherapy (77750–77790) includes radiation treatment management (77427 and 77431) and continuing medical physics (77336). NCCI bundles into radiation therapy services the items that the Claims Processing Manual, Chapter 13, §70.2, lists as included in treatment management.
The practical rule: during a brachytherapy-only course, do not add 77427. During a combined course, bill 77427 based on the external beam fractions only, and keep the fraction count clean in the claim narrative.
The ICD-10-CM Official Guidelines for FY 2027 (effective October 1, 2026) are direct. Z51.0, Encounter for antineoplastic radiation therapy, is assigned first when an encounter is chiefly for external beam radiation. When the admission or encounter is for insertion or implantation of radioactive elements (for example, brachytherapy), the malignancy is sequenced as the principal or first-listed diagnosis, and Z51.0 should not be assigned. If the patient develops complications during that admission, such as uncontrolled nausea, vomiting, or dehydration, the malignancy stays first and the complication codes follow.
Check your encounter templates. Many systems default Z51.0 for every radiation oncology visit. On implant and insertion days, that default is wrong.
Only a few modifiers are verified for this code family. Use them deliberately.
Modifiers do not unlock bundled services. A modifier on 77300 next to an HDR code, or on 77790 next to 77778, does not make the service separately payable. It just moves the error from the edit to an audit.
Use this as a chart-to-claim audit for each brachytherapy course.
These are educational patterns, not payment guarantees. Always confirm current CMS, Noridian JF, and payer rules for the date of service.
Example A: Vaginal cuff HDR, freestanding center. A post-hysterectomy endometrial cancer patient receives three HDR fractions on separate days with a single-channel vaginal cylinder, one unit of 77770 each day. The course includes a decision visit (E/M), 77263, a simulation, 77316 (one channel), and 57156 for cylinder insertion at each fraction. Do not add 77300, 77790, 77427, or 77336. The cancer is the first-listed diagnosis on the insertion and treatment encounters.
Example B: Permanent prostate seed implant, hospital outpatient. The urologist bills 55875 (090 global). The radiation oncologist applies the seeds in the same session and bills 77778-26, 76965-26 if they performed the guidance, and the brachytherapy plan with modifier 26. The hospital reports 55875, 77778, the isodose plan, and a C-code line for the seeds, with units equal to the number of seeds implanted, including each seed in a strand. Because 55875 has status indicator J1, the other covered services on that claim are packaged into the comprehensive APC payment. The seed lines are the exception: they pay separately. Do not add 77790 or 77300 to 77778.
Example C: Accelerated partial breast HDR, twice daily. A surgeon places a multi-catheter interstitial breast device. The radiation oncologist bills 77290 for the first simulation and 77280 for later simulations, per NCCI. Each treatment day has two HDR fractions, reported as two units of 77771 or 77772 depending on the channel count, within the MUE of 2. If the device has 14 catheters treated, that is 77772. If it has 10, that is 77771. Weekly management and 77300 are not billed.
No. ASTRO’s FAQ says 77300 cannot be billed with 77316–77318 or 77770–77772, and NCCI says 77300 is integral to 77767–77772 and 77778.
NCCI says 77336 is included in brachytherapy in general. It may be reported for concurrent external beam treatments, and it may be separately reportable for multi-step brachytherapy.
We found none on Noridian’s JF active LCD list (updated October 1, 2026) or its coverage article list. Washington Part B (contract 02402) brachytherapy claims follow national CMS rules, NCCI policy, and MUEs. The only radiation-related LCD on that list, L40176, addresses superficial treatment of nonmelanoma skin cancer and states that electronic brachytherapy for that use is not reasonable and necessary.
Only if the radiation oncologist also applies the source at that same encounter. Otherwise, NCCI points to a non-brachytherapy code for the intraoperative work, or to 77770–77772 if the source is applied after surgery in a different room.
Two. The Q4 2026 MUE for 77767–77772 is 2 per day. NCCI specifically recognizes twice-daily partial breast HDR.
No. Brachytherapy sources carry OPPS status indicator U, are paid per unit, and are excluded from comprehensive APC packaging. Bill each seed in a strand as one unit.
Brachytherapy billing is a bundling discipline. The radionuclide brachytherapy codes checked here are active for 2026. The confirmed change is skin eBT, which moved out of 0394T and into the surface radiation family. Payment depends on whether your team knows what each code already includes. HDR delivery includes basic dosimetry and source handling. Every brachytherapy code includes treatment management and, in general, weekly physics. The intracavitary application codes (77761–77763) and the infusion code (77750) carry a 90-day global. Hospital sources pay only when billed per unit. Implant encounters list the cancer first. Build those rules into charge capture, and brachytherapy claims stop bouncing.
ALH Billing Solutions works with radiation oncology practices on charge capture, coding review, and denial management. For brachytherapy, that means checking HDR and LDR templates against current NCCI, MUE, and global-period rules, cleaning hospital source lines and units, and working denials before they age. If brachytherapy claims are stalling or underpaying, start with a free A/R Health Check. Email info@alhbillingsolutions.com or call 360-836-1413.
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