Billing code 77439: Radiation image guidanceMedicare rate & RVUs in Illinois
This add-on reports ultrasound image guidance for placement during surface radiation therapy, alongside the applicable primary radiation delivery service.
Medicare pays $15.51–$16.26 for 77439 in the office in Illinois, from Rest Of Illinois to Suburban Chicago. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
On this page 9 sections
What 77439 covers
This service covers ultrasound-based image guidance used to place or position equipment for surface radiation therapy. It is associated with treatment delivery for superficial or orthovoltage radiation, including treatment of cutaneous lesions. A radiation oncologist or other qualified clinician may perform and interpret the imaging, with technical staff and ultrasound equipment supporting the technical portion in a radiation oncology setting.
Report 77439 only with its primary radiation treatment service; select the primary delivery code based on the treatment type, such as superficial treatment at 150 kV or less versus orthovoltage treatment above 150 through 500 kV. The record should support the ultrasound-guided placement and the imaging service provided. CMS identifies professional and technical components: modifier 26 reports interpretation, modifier TC reports equipment and staff, and no modifier represents the global service. As an add-on, payment is within the primary procedure's global period.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where 77439 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
4 payment localities
$15.51 to $16.26
| Payment locality | Office | Facility |
|---|---|---|
| Chicago | $16.13 | Unavailable |
| East St. Louis | $15.55 | Unavailable |
| Rest Of Illinois | $15.51 | Unavailable |
| Suburban Chicago | $16.26 | Unavailable |
How the 77439 rate is calculated
Each of 77439’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 77439
RVUs × geographic indexes × conversion factor
Work0.30
0.30 RVUs× 1.000 GPCI
Practice expense0.18
0.18 RVUs× 1.000 GPCI
Malpractice0.00
0.00 RVUs× 1.000 GPCI
Adjusted RVUs
0.4800
Conversion factor
$33.4009
Medicare rate
$16.03
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 77439
The CMS indicators that decide how 77439 is paid alongside other services.
CMS payment indicators · 77439
Radiation image guidance
| Rule | CMS value | What it means |
|---|---|---|
| Global period | ZZZ | Add-on code: falls within the primary procedure’s global period. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 1 | Diagnostic test with separate professional (26) and technical (TC) components. |
What modifiers do to the payment
Modifier 26 · payment effect
With and without the modifier
77439 without 26 · national office
$16.03
Radiation image guidance
77439-26 · Professional component
$16.03
Pays only the interpretation and report.
77439 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 77437Superficial radiation
- 77437 reports superficial radiation delivery at 150 kV or less. 77439 is an add-on for ultrasound-based placement guidance and is not a substitute for delivery.
- 77438Superficial radiation
- 77438 reports orthovoltage delivery above 150 through 500 kV. Use 77439 for the associated ultrasound placement guidance, not to represent the delivery itself.
- 77417Ther radiology port image(s)
- 77417 reports therapeutic radiology port imaging. 77439 concerns ultrasound-based placement guidance for surface radiation treatment.
77439 billing questions
Which primary service should accompany 77439?
Report it with the applicable primary surface radiation delivery service. The primary code depends on the treatment type, including whether the radiation is superficial or orthovoltage.
Can 77439 be reported by itself?
No. CMS identifies it as an add-on that must be billed with a primary procedure, and payment falls within that procedure's global period.
When should modifier 26 or TC be used?
Use modifier 26 for the professional interpretation and modifier TC for the technical service, including equipment and staff. Reporting without a modifier represents the global service.
What documentation supports this service?
Document the ultrasound-guided placement performed and the imaging interpretation when billing the professional component. The record should also identify the accompanying surface radiation treatment service.
Is 77439 the same as radiation port imaging?
No. 77439 describes ultrasound-based placement guidance for surface radiation therapy; 77417 describes therapeutic radiology port imaging.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file lines behind this rate
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