CPT code 78650: CSF leak imaging, leak detection and localization2026 Medicare rate & RVUs in Missouri
Reports nuclear medicine imaging performed to detect and localize a suspected cerebrospinal fluid leak, such as leakage from the cranial or spinal CSF space.
Medicare pays $214.31–$234.46 for 78650 in the office in Missouri, from Rest of Missouri to Metropolitan St. Louis, MO. 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 78650 covers
This nuclear medicine study traces cerebrospinal fluid to identify and localize a suspected leak. It may be used when a patient has signs of CSF leakage, including persistent clear drainage after head or spinal surgery or trauma. A radiologist or nuclear medicine physician interprets the resulting images; the technical service involves the imaging equipment and staff. The study is generally performed in a hospital or imaging department equipped for nuclear medicine procedures.
Select 78650 when the diagnostic purpose is finding and locating a CSF leak, rather than evaluating general CSF circulation, ventricular anatomy, or shunt function. Documentation should identify the suspected leak, the imaging procedure performed, and the physician’s interpretation and findings. Medicare recognizes professional and technical components: report modifier 26 for interpretation, modifier TC for equipment and staff, or no modifier for the global service when one entity provides both.
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 78650 pays more and less in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
3 payment localities
$214.31 to $234.46
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | $231.50 | Unavailable |
| Metropolitan St. Louis, MO | $234.46 | Unavailable |
| Rest of Missouri | $214.31 | Unavailable |
How the 78650 rate is calculated
Each of 78650’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 · 78650
RVUs × geographic indexes × conversion factor
Work0.59
0.59 RVUs× 1.000 GPCI
Practice expense6.68
6.68 RVUs× 1.000 GPCI
Malpractice0.07
0.07 RVUs× 1.000 GPCI
Adjusted RVUs
7.3400
Conversion factor
$33.4009
Medicare rate
$245.16
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 78650
The CMS indicators that decide how 78650 is paid alongside other services.
CMS payment indicators · 78650
CSF leak imaging, leak detection and localization
| 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
78650 without 26 · national office
$245.16
CSF leak imaging, leak detection and localization
78650-26 · Professional component
$23.71
Pays only the interpretation and report.
78650 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 78630CSF scanCisternography
- Choose 78650 when the study is specifically intended to find and localize a CSF leak. Choose 78630 for a cisternographic CSF study.
- 78645CSF shunt studyShunt patency assessment
- 78645 evaluates a CSF shunt; 78650 investigates suspected leakage from the CSF space.
- 78635CSF imagingVentricular flow study
- 78635 is radiopharmaceutical ventriculography focused on the ventricular system. 78650 is directed at detecting and localizing CSF leakage.
78650 billing questions
When should 78650 be chosen over 78630?
Use 78650 when the study is directed at detecting and localizing a CSF leak. Code 78630 describes cisternography when the purpose is a CSF cisternographic study rather than targeted leak localization.
How are the professional and technical services reported?
Report modifier 26 for the physician’s interpretation and modifier TC for the technical service. Report the code without a modifier when billing the global service.
What documentation supports 78650?
Document the clinical suspicion of a CSF leak, the imaging performed to locate it, and the interpreting physician’s findings. The record should make clear that leak detection or localization was the study’s purpose.
Is 78650 the code for evaluating a CSF shunt?
No. 78650 addresses suspected CSF leakage; 78645 is for evaluation of a CSF shunt.
Can the professional and technical components be billed separately?
Yes. Medicare identifies separately priced professional and technical components for this diagnostic test, reported with modifiers 26 and TC, respectively.
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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