CPT code 78630: CSF scan, cisternography2026 Medicare rate & RVUs in Guam
A radionuclide cerebrospinal fluid scan tracks tracer movement through CSF spaces to assess circulation when a clinician needs functional imaging.
Medicare pays $330.07 for 78630 in the office in Guam (Hawaii, Guam, HI). 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.
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On this page 9 sections
What 78630 covers
This nuclear medicine study follows a radiotracer through cerebrospinal fluid spaces after intrathecal administration, with images obtained to evaluate CSF circulation and distribution. It is typically performed in a hospital nuclear medicine department or imaging center, with a nuclear medicine physician or radiologist interpreting the study. A clinician may request it when the diagnostic question concerns how CSF moves through the intracranial spaces rather than brain tissue appearance or shunt function alone.
Report 78630 for the CSF scan itself; the medical record should support the clinical question, the study performed, and the interpreting physician’s findings. CMS recognizes professional and technical components: report modifier 26 for the interpretation, TC for the equipment and staff, or neither modifier when billing the global service. The professional and technical services may be billed separately when performed by different entities. The scan’s findings should be distinguished from a targeted CSF leak study, ventricular study, or shunt evaluation when selecting among related nuclear medicine services.
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.
78630 in Hawaii, Guam, HI
| Payment locality | Office | Facility |
|---|---|---|
| Hawaii, Guam, HI | $330.07 | Unavailable |
How the 78630 rate is calculated
Each of 78630’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 · 78630
RVUs × geographic indexes × conversion factor
Work0.66
0.66 RVUs× 1.000 GPCI
Practice expense8.06
8.06 RVUs× 1.000 GPCI
Malpractice0.10
0.10 RVUs× 1.000 GPCI
Adjusted RVUs
8.8200
Conversion factor
$33.4009
Medicare rate
$294.60
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 78630
The CMS indicators that decide how 78630 is paid alongside other services.
CMS payment indicators · 78630
CSF scan, cisternography
| Rule | CMS value | What it means |
|---|---|---|
| Global period | XXX | The global surgery concept doesn’t apply. |
| 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
78630 without 26 · national office
$294.60
CSF scan, cisternography
78630-26 · Professional component
$30.73
Pays only the interpretation and report.
78630 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 78635CSF imagingVentricular flow study
- 78630 assesses tracer movement through CSF spaces; 78635 is the ventricular-focused CSF study.
- 78645CSF shunt studyShunt patency assessment
- Use 78645 when the study evaluates a CSF shunt. Code 78630 for a scan addressing CSF circulation and distribution.
- 78650CSF leak imagingLeak detection and localization
- 78650 is directed at CSF leakage imaging; 78630 describes the broader CSF scan.
78630 billing questions
How does 78630 differ from a CSF leak study?
78630 describes a CSF scan assessing tracer movement through CSF spaces. Use 78650 when the imaging service is specifically a CSF leakage study.
When should 78635 be considered instead?
78635 is for CSF ventriculography, a ventricular-focused study. Choose based on the study actually performed and its diagnostic target, not just the fact that both involve CSF.
Can the professional and technical services be billed separately?
Yes. Modifier 26 identifies the professional interpretation, and TC identifies the technical service; billing without either modifier represents the global service.
What documentation supports 78630?
The record should identify the clinical question about CSF circulation, the scan performed, and the interpreting physician’s findings.
Is 78630 the code for evaluating a CSF shunt?
No. 78645 describes CSF shunt evaluation; 78630 reports a scan focused on CSF circulation and distribution.
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
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