Billing code 78635: CSF imagingMedicare rate & RVUs
Nuclear imaging tracks radiotracer movement through ventricular cerebrospinal fluid when clinicians need to assess flow within the brain’s ventricular system.
Medicare pays $294.60 for 78635 nationally in the office. Local office rates run $254.92–$415.84.
Medicare rate · 78635
CSF imaging
Swap in your local Medicare rate.
- Work RVUs
- 0.59
- Total RVUs
- 8.82
- Global days
- XXX
National rate · 2026
$294.60
Office setting, before claim adjustments.
See every locality for 78635 → · Billed by an NP, PA or therapist? →
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 10 sections
What 78635 covers
This nuclear medicine study follows radiotracer distribution through cerebrospinal fluid in the ventricular system. It is used when clinicians need information about ventricular CSF flow, such as in evaluating a suspected flow abnormality. A nuclear medicine physician interprets the images; the study may involve ventricular access for tracer administration, with imaging performed in a nuclear medicine department.
Report 78635 for the ventricular CSF imaging service, rather than a general brain scan or a study focused on shunt function or CSF leakage. The record should support the clinical question, tracer administration and access route, images obtained, and the physician’s interpretation. CMS recognizes a professional component, reported with modifier 26 for interpretation, and a technical component, reported with modifier TC for equipment and staff. Without either modifier, the claim represents the global service.
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 78635 pays more and less
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
109 payment localities
$254.92 to $415.84
109 of 109 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Alabama | $259.41 | Unavailable |
| Alaska* | $320.94 | Unavailable |
| Arizona | $285.77 | Unavailable |
| Arkansas | $254.92 | Unavailable |
| Atlanta | $299.55 | Unavailable |
| Austin | $310.12 | Unavailable |
| Bakersfield | $320.06 | Unavailable |
| Baltimore/Surr. Cntys | $315.42 | Unavailable |
| Beaumont | $269.91 | Unavailable |
| Brazoria | $291.72 | Unavailable |
| Chicago | $299.56 | Unavailable |
| Chico | $319.82 | Unavailable |
| Colorado | $311.67 | Unavailable |
| Connecticut | $316.51 | Unavailable |
| Dallas | $293.30 | Unavailable |
| Dc + Md/Va Suburbs | $344.42 | Unavailable |
| Delaware | $291.16 | Unavailable |
| Detroit | $286.90 | Unavailable |
| East St. Louis | $275.53 | Unavailable |
| El Centro | $319.84 | Unavailable |
| Fort Lauderdale | $300.29 | Unavailable |
| Fort Worth | $290.62 | Unavailable |
| Fresno | $319.82 | Unavailable |
| Galveston | $292.39 | Unavailable |
| Hanford-Corcoran | $319.82 | Unavailable |
| Hawaii, Guam | $330.76 | Unavailable |
| Houston | $293.85 | Unavailable |
| Idaho | $271.41 | Unavailable |
| Indiana | $273.35 | Unavailable |
| Iowa | $269.85 | Unavailable |
| Kansas | $267.14 | Unavailable |
| Kentucky | $264.15 | Unavailable |
| Los Angeles-Long Beach-Anaheim (Los Angeles/Orange Cnty) | $344.32 | Unavailable |
| Madera | $319.82 | Unavailable |
| Manhattan | $341.52 | Unavailable |
| Merced | $319.82 | Unavailable |
| Metropolitan Boston | $347.92 | Unavailable |
| Metropolitan Kansas City | $277.93 | Unavailable |
| Metropolitan Philadelphia | $306.63 | Unavailable |
| Metropolitan St. Louis | $281.53 | Unavailable |
| Miami | $309.84 | Unavailable |
| Minnesota | $300.61 | Unavailable |
| Mississippi | $256.06 | Unavailable |
| Modesto | $319.82 | Unavailable |
| Montana** | $294.59 | Unavailable |
| Napa | $381.09 | Unavailable |
| Nebraska | $271.97 | Unavailable |
| Nevada** | $294.42 | Unavailable |
| New Hampshire | $305.42 | Unavailable |
| New Mexico | $272.54 | Unavailable |
| New Orleans | $278.90 | Unavailable |
| North Carolina | $275.39 | Unavailable |
| North Dakota** | $293.01 | Unavailable |
| Northern Nj | $339.57 | Unavailable |
| Nyc Suburbs/Long Island | $349.60 | Unavailable |
| Ohio | $270.93 | Unavailable |
| Oklahoma | $264.87 | Unavailable |
| Oxnard-Thousand Oaks-Ventura | $343.68 | Unavailable |
| Portland | $324.44 | Unavailable |
| Poughkpsie/N Nyc Suburbs | $321.90 | Unavailable |
| Puerto Rico | $297.55 | Unavailable |
| Queens | $346.58 | Unavailable |
| Redding | $319.82 | Unavailable |
| Rest Of California | $319.82 | Unavailable |
| Rest Of Florida | $283.96 | Unavailable |
| Rest Of Georgia | $265.71 | Unavailable |
| Rest Of Illinois | $272.42 | Unavailable |
| Rest Of Louisiana | $263.18 | Unavailable |
| Rest Of Maine | $271.81 | Unavailable |
| Rest Of Maryland | $297.84 | Unavailable |
| Rest Of Massachusetts | $308.80 | Unavailable |
| Rest Of Michigan | $271.26 | Unavailable |
| Rest Of Missouri | $256.96 | Unavailable |
| Rest Of New Jersey | $320.69 | Unavailable |
| Rest Of New York | $280.19 | Unavailable |
| Rest Of Oregon | $292.71 | Unavailable |
| Rest Of Pennsylvania | $272.13 | Unavailable |
| Rest Of Texas | $280.45 | Unavailable |
| Rest Of Washington | $308.64 | Unavailable |
| Rhode Island | $303.66 | Unavailable |
| Riverside-San Bernardino-Ontario | $320.69 | Unavailable |
| Sacramento-Roseville-Folsom | $338.44 | Unavailable |
| Salinas | $337.25 | Unavailable |
| San Diego-Chula Vista-Carlsbad | $347.32 | Unavailable |
| San Francisco-Oakland-Berkeley (Marin Cnty) | $406.63 | Unavailable |
| San Francisco-Oakland-Berkeley (San Francisco/San Mateo/Alameda/Contra Costa Cnty) | $406.54 | Unavailable |
| San Jose-Sunnyvale-Santa Clara (San Benito Cnty) | $415.84 | Unavailable |
| San Jose-Sunnyvale-Santa Clara (Santa Clara Cnty) | $415.47 | Unavailable |
| San Luis Obispo-Paso Robles | $331.53 | Unavailable |
| Santa Cruz-Watsonville | $352.30 | Unavailable |
| Santa Maria-Santa Barbara | $339.10 | Unavailable |
| Santa Rosa-Petaluma | $356.01 | Unavailable |
| Seattle (King Cnty) | $356.89 | Unavailable |
| South Carolina | $273.51 | Unavailable |
| South Dakota** | $292.82 | Unavailable |
| Southern Maine | $291.16 | Unavailable |
| Stockton | $319.82 | Unavailable |
| Suburban Chicago | $304.15 | Unavailable |
| Tennessee | $268.59 | Unavailable |
| Utah | $277.99 | Unavailable |
| Vallejo | $380.96 | Unavailable |
| Vermont | $290.55 | Unavailable |
| Virgin Islands | $297.55 | Unavailable |
| Virginia | $289.18 | Unavailable |
| Visalia | $319.82 | Unavailable |
| West Virginia | $260.09 | Unavailable |
| Wisconsin | $281.31 | Unavailable |
| Wyoming** | $293.90 | Unavailable |
| Yuba City | $319.82 | Unavailable |
78635 rates by state
Office rate range in each state. Select a state to see its payment localities.
Explore a state
Local rates. Clear comparisons.
Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.
$254.92
$367.83
Color shows the midpoint of each state’s locality range.
View every state and territory as a table
| State / territory | Office rate range | Localities |
|---|---|---|
| AK | $320.94 | 1 |
| AL | $259.41 | 1 |
| AR | $254.92 | 1 |
| AZ | $285.77 | 1 |
| CA | $319.82–$415.84 | 29 |
| CO | $311.67 | 1 |
| CT | $316.51 | 1 |
| DC | $344.42 | 1 |
| DE | $291.16 | 1 |
| FL | $283.96–$309.84 | 3 |
| GA | $265.71–$299.55 | 2 |
| GU | $330.76 | 1 |
| HI | $330.76 | 1 |
| IA | $269.85 | 1 |
| ID | $271.41 | 1 |
| IL | $272.42–$304.15 | 4 |
| IN | $273.35 | 1 |
| KS | $267.14 | 1 |
| KY | $264.15 | 1 |
| LA | $263.18–$278.90 | 2 |
| MA | $308.80–$347.92 | 2 |
| MD | $297.84–$344.42 | 3 |
| ME | $271.81–$291.16 | 2 |
| MI | $271.26–$286.90 | 2 |
| MN | $300.61 | 1 |
| MO | $256.96–$281.53 | 3 |
| MS | $256.06 | 1 |
| MT | $294.59 | 1 |
| NC | $275.39 | 1 |
| ND | $293.01 | 1 |
| NE | $271.97 | 1 |
| NH | $305.42 | 1 |
| NJ | $320.69–$339.57 | 2 |
| NM | $272.54 | 1 |
| NV | $294.42 | 1 |
| NY | $280.19–$349.60 | 5 |
| OH | $270.93 | 1 |
| OK | $264.87 | 1 |
| OR | $292.71–$324.44 | 2 |
| PA | $272.13–$306.63 | 2 |
| PR | $297.55 | 1 |
| RI | $303.66 | 1 |
| SC | $273.51 | 1 |
| SD | $292.82 | 1 |
| TN | $268.59 | 1 |
| TX | $269.91–$310.12 | 8 |
| UT | $277.99 | 1 |
| VA | $289.18–$344.42 | 2 |
| VI | $297.55 | 1 |
| VT | $290.55 | 1 |
| WA | $308.64–$356.89 | 2 |
| WI | $281.31 | 1 |
| WV | $260.09 | 1 |
| WY | $293.90 | 1 |
How the 78635 rate is calculated
Each of 78635’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 · 78635
RVUs × geographic indexes × conversion factor
Swap in your local Medicare rate.
Work 0.59Practice expense 8.15Malpractice 0.08
All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.
Payment rules and modifiers for 78635
The CMS indicators that decide how 78635 is paid alongside other services.
CMS payment indicators · 78635
CSF imaging
| 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
78635 without 26 · national office
$294.60
CSF imaging
78635-26 · Professional component
$28.06
Pays only the interpretation and report.
78635 compared with similar codes
Compare codes
78635 vs 78630 vs 78645 vs 78650: national Medicare rates
Swap in your local Medicare rate.
How to choose
- 78630CSF scan
- Choose 78635 for imaging focused on ventricular CSF flow. Code 78630 describes a CSF scan using a different approach to assess CSF circulation.
- 78645CSF shunt study
- Use 78645 when the study evaluates a CSF shunt. Use 78635 for ventricular CSF imaging when shunt function is not the specific study target.
- 78650CSF leak imaging
- Code 78650 is for imaging directed at a suspected CSF leak; 78635 focuses on CSF movement through the ventricles.
78635 billing questions
How does 78635 differ from a CSF scan?
78635 describes imaging focused on CSF movement through the ventricular system. A CSF scan such as 78630 is used for a different CSF imaging approach and clinical question.
When should 78645 be considered instead?
Use 78645 when the study evaluates CSF shunt function. Code 78635 describes ventricular CSF imaging, not a shunt-specific evaluation.
Can the professional and technical portions be billed separately?
Yes. Report modifier 26 for the physician’s interpretation or TC for the technical service, which includes equipment and staff. Billing without a modifier represents the global service.
What documentation supports reporting 78635?
Document the reason for evaluating ventricular CSF flow, the tracer administration and access route, the imaging performed, and the interpreting physician’s findings.
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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