CPT code 78645: CSF shunt study, shunt patency assessment2026 Medicare rate & RVUs in Idaho
Nuclear medicine imaging tracks radiotracer movement through a cerebrospinal fluid shunt to investigate suspected impaired flow or shunt malfunction.
In Idaho, Medicare pays $262.73 for 78645 in the office.
Check a contract rate as a % of Medicare · 78645 nationwide
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 11 sections
What 78645 covers
This study evaluates flow through an implanted cerebrospinal fluid shunt, commonly when symptoms or other findings raise concern for obstruction or malfunction. A nuclear medicine team administers radiotracer through the shunt access point and obtains images to follow its movement through the shunt pathway. The study may help assess whether flow is occurring and where it appears impaired.
Report 78645 for the shunt-focused radionuclide evaluation, rather than a study directed at general CSF circulation, ventricular imaging, or leak localization. Documentation should identify the clinical concern, the shunt evaluated, the radiotracer administration and imaging performed, and the interpretation of tracer progression. CMS recognizes professional and technical components: report modifier 26 for the interpretation, modifier TC for equipment and staff, or no component modifier for the global service. The professional and technical components are separately priced.
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.
How Idaho compares for 78645
Across 109 of 109 payment localities, the office rate for 78645 runs from $246.74 in Arkansas to $402.69 in San Benito County, CA. Idaho pays $262.73. The RVUs are the same everywhere; the geographic indexes change the dollars.
- Idaho · this page$262.73
- Los Angeles, CA · California$333.40+$70.67
- Washington, DC area · District of Columbia$333.52+$70.79
- Miami, FL · Florida$300.15+$37.42
- Chicago, IL · Illinois$290.15+$27.42
- Manhattan, NY · New York$330.75+$68.02
- Alaska · Alaska$310.55+$47.82
Other areas in Idaho first, then benchmark localities. Bars start at $0.
Every other payment area
| Payment locality | Office | Facility |
|---|---|---|
| AlabamaAlabama | $251.10 | — |
| ArkansasArkansas | $246.74 | — |
| ArizonaArizona | $276.68 | — |
| Bakersfield, CACalifornia | $309.89 | — |
| Chico, CACalifornia | $309.65 | — |
| El Centro, CACalifornia | $309.67 | — |
| Fresno, CACalifornia | $309.65 | — |
| Hanford, CACalifornia | $309.65 | — |
| Madera, CACalifornia | $309.65 | — |
| Merced, CACalifornia | $309.65 | — |
| Modesto, CACalifornia | $309.65 | — |
| Napa, CACalifornia | $369.02 | — |
| Oxnard, CACalifornia | $332.78 | — |
| Redding, CACalifornia | $309.65 | — |
| Rest of CaliforniaCalifornia | $309.65 | — |
| Riverside, CACalifornia | $310.52 | — |
| Sacramento, CACalifornia | $327.69 | — |
| Salinas, CACalifornia | $326.54 | — |
| San Diego, CACalifornia | $336.30 | — |
| Marin County, CACalifornia | $393.76 | — |
| San Francisco, CACalifornia | $393.67 | — |
| San Benito County, CACalifornia | $402.69 | — |
| Santa Clara County, CACalifornia | $402.32 | — |
| San Luis Obispo, CACalifornia | $321.00 | — |
| Santa Cruz, CACalifornia | $341.13 | — |
| Santa Maria, CACalifornia | $328.33 | — |
| Santa Rosa, CACalifornia | $344.73 | — |
| Stockton, CACalifornia | $309.65 | — |
| Vallejo, CACalifornia | $368.89 | — |
| Visalia, CACalifornia | $309.65 | — |
| Yuba City, CACalifornia | $309.65 | — |
| ColoradoColorado | $301.77 | — |
| ConnecticutConnecticut | $306.50 | — |
| DelawareDelaware | $281.90 | — |
| Fort Lauderdale, FLFlorida | $290.83 | — |
| Rest of FloridaFlorida | $274.98 | — |
| Atlanta, GAGeorgia | $290.06 | — |
| Rest of GeorgiaGeorgia | $257.26 | — |
| Hawaii, Guam, HIHawaii | $320.27 | — |
| IowaIowa | $261.20 | — |
| East St. Louis, ILIllinois | $266.84 | — |
| Rest of IllinoisIllinois | $263.79 | — |
| Suburban Chicago, ILIllinois | $294.56 | — |
| IndianaIndiana | $264.61 | — |
| KansasKansas | $258.59 | — |
| KentuckyKentucky | $255.73 | — |
| New Orleans, LALouisiana | $270.04 | — |
| Rest of LouisianaLouisiana | $254.79 | — |
| Metropolitan Boston, MAMassachusetts | $336.91 | — |
| Rest of MassachusettsMassachusetts | $298.99 | — |
| Baltimore area, MDMaryland | $305.44 | — |
| Rest of MarylandMaryland | $288.38 | — |
| Rest of MaineMaine | $263.12 | — |
| Southern Maine, MEMaine | $281.88 | — |
| Detroit, MIMichigan | $277.84 | — |
| Rest of MichiganMichigan | $262.63 | — |
| MinnesotaMinnesota | $291.01 | — |
| Metropolitan Kansas City, MOMissouri | $269.09 | — |
| Metropolitan St. Louis, MOMissouri | $272.58 | — |
| Rest of MissouriMissouri | $248.76 | — |
| MississippiMississippi | $247.87 | — |
| MontanaMontana | $285.24 | — |
| North CarolinaNorth Carolina | $266.60 | — |
| North DakotaNorth Dakota | $283.66 | — |
| NebraskaNebraska | $263.26 | — |
| New HampshireNew Hampshire | $295.73 | — |
| Northern New JerseyNew Jersey | $328.82 | — |
| Rest of New JerseyNew Jersey | $310.53 | — |
| New MexicoNew Mexico | $263.88 | — |
| NevadaNevada | $285.06 | — |
| NYC suburbs and Long Island, NYNew York | $338.60 | — |
| Poughkeepsie and northern NYC suburbs, NYNew York | $311.71 | — |
| Queens, NYNew York | $335.65 | — |
| Rest of New YorkNew York | $271.26 | — |
| OhioOhio | $262.31 | — |
| OklahomaOklahoma | $256.41 | — |
| Portland, OROregon | $314.15 | — |
| Rest of OregonOregon | $283.39 | — |
| Metropolitan Philadelphia, PAPennsylvania | $296.91 | — |
| Rest of PennsylvaniaPennsylvania | $263.46 | — |
| Puerto RicoPuerto Rico | $288.11 | — |
| Rhode IslandRhode Island | $294.02 | — |
| South CarolinaSouth Carolina | $264.79 | — |
| South DakotaSouth Dakota | $283.47 | — |
| TennesseeTennessee | $259.99 | — |
| Austin, TXTexas | $300.28 | — |
| Beaumont, TXTexas | $261.31 | — |
| Brazoria, TXTexas | $282.43 | — |
| Dallas, TXTexas | $283.98 | — |
| Fort Worth, TXTexas | $281.37 | — |
| Galveston, TXTexas | $283.09 | — |
| Houston, TXTexas | $284.55 | — |
| Rest of TexasTexas | $271.53 | — |
| UtahUtah | $269.14 | — |
| VirginiaVirginia | $279.97 | — |
| Virgin Islands, VIUnited States Virgin Islands | $288.11 | — |
| VermontVermont | $281.29 | — |
| Rest of WashingtonWashington | $298.83 | — |
| King County, WAWashington | $345.59 | — |
| WisconsinWisconsin | $272.31 | — |
| West VirginiaWest Virginia | $251.83 | — |
| WyomingWyoming | $284.55 | — |
78645 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.
$246.74
$356.17
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 | $310.55 | 1 |
| AL | $251.10 | 1 |
| AR | $246.74 | 1 |
| AZ | $276.68 | 1 |
| CA | $309.65–$402.69 | 29 |
| CO | $301.77 | 1 |
| CT | $306.50 | 1 |
| DC | $333.52 | 1 |
| DE | $281.90 | 1 |
| FL | $274.98–$300.15 | 3 |
| GA | $257.26–$290.06 | 2 |
| GU | $320.27 | 1 |
| HI | $320.27 | 1 |
| IA | $261.20 | 1 |
| ID | $262.73 | 1 |
| IL | $263.79–$294.56 | 4 |
| IN | $264.61 | 1 |
| KS | $258.59 | 1 |
| KY | $255.73 | 1 |
| LA | $254.79–$270.04 | 2 |
| MA | $298.99–$336.91 | 2 |
| MD | $288.38–$333.52 | 3 |
| ME | $263.12–$281.88 | 2 |
| MI | $262.63–$277.84 | 2 |
| MN | $291.01 | 1 |
| MO | $248.76–$272.58 | 3 |
| MS | $247.87 | 1 |
| MT | $285.24 | 1 |
| NC | $266.60 | 1 |
| ND | $283.66 | 1 |
| NE | $263.26 | 1 |
| NH | $295.73 | 1 |
| NJ | $310.53–$328.82 | 2 |
| NM | $263.88 | 1 |
| NV | $285.06 | 1 |
| NY | $271.26–$338.60 | 5 |
| OH | $262.31 | 1 |
| OK | $256.41 | 1 |
| OR | $283.39–$314.15 | 2 |
| PA | $263.46–$296.91 | 2 |
| PR | $288.11 | 1 |
| RI | $294.02 | 1 |
| SC | $264.79 | 1 |
| SD | $283.47 | 1 |
| TN | $259.99 | 1 |
| TX | $261.31–$300.28 | 8 |
| UT | $269.14 | 1 |
| VA | $279.97–$333.52 | 2 |
| VI | $288.11 | 1 |
| VT | $281.29 | 1 |
| WA | $298.83–$345.59 | 2 |
| WI | $272.31 | 1 |
| WV | $251.83 | 1 |
| WY | $284.55 | 1 |
How the 78645 rate is calculated
Each of 78645’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 · 78645
RVUs × geographic indexes × conversion factor
Work0.56
0.56 RVUs× 1.000 GPCI
Practice expense7.90
7.90 RVUs× 1.000 GPCI
Malpractice0.08
0.08 RVUs× 1.000 GPCI
Adjusted RVUs
8.5400
Conversion factor
$33.4009
Medicare rate
$285.24
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
The exact Idaho inputs and CMS source lines
PPRRVU2026_Oct_nonQPP.csv
9,470
- Code
- 78645
- Physician work
- 0.56
- Practice expense
- 7.90
- Malpractice
- 0.08
GPCI2026.csv
47
- Locality
- Idaho
- Physician work
- 1.000
- Practice expense
- 0.920
- Malpractice
- 0.473
| Component | RVU | Locality factor | Adjusted |
|---|---|---|---|
| Physician work | 0.56 | × 1.000 | 0.5600 |
| Practice expense | 7.90 | × 0.920 | 7.2680 |
| Malpractice | 0.08 | × 0.473 | 0.0378 |
| Total RVUs | 7.8658 | ||
| Conversion factor | × 33.4009 | ||
Office rate, Idaho$262.73
Office: (0.56 × 1 + 7.9 × 0.92 + 0.08 × 0.473) × $33.4009 = $262.73
Payment rules and modifiers for 78645
The CMS indicators that decide how 78645 is paid alongside other services.
CMS payment indicators · 78645
CSF shunt study, shunt patency assessment
| 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
78645 without 26 · national office
$285.24
CSF shunt study, shunt patency assessment
78645-26 · Professional component
$25.72
Pays only the interpretation and report.
How 78645 has changed in Idaho
78645 · Office / nonfacility
$262.73
Effective 2026-10-01
The base rate is $6.67 higher than on 2025-10-01, moving from $256.06 to $262.73 (2.6%).
It is unchanged from the immediately preceding available release, effective 2026-07-01.
One bar per available release, ordered by effective date. Missing rates remain gaps. These comparisons hold the code, setting and locality identifiers constant; they do not isolate which policy or input caused a change.
What changed, release by release
January 1, 2026
RVU26A
$256.06changed to$262.73
- Conversion factor 32.3465 changed to 33.4009
- Work RVU 0.57 changed to 0.56
- Practice expense RVU 8.05 changed to 7.90
- Practice expense GPCI 0.908 changed to 0.920
- Malpractice GPCI 0.461 changed to 0.473
Held through RVU26B, RVU26C, RVU26D.
January 1, 2025
RVU25A
$268.20changed to$256.06
- Conversion factor 33.2875 changed to 32.3465
- Practice expense RVU 8.20 changed to 8.05
- Malpractice RVU 0.09 changed to 0.08
Held through RVU25B, RVU25C, RVU25D.
March 9, 2024
RVU24AR
$263.82changed to$268.20
- Conversion factor 32.7442 changed to 33.2875
Held through RVU24B, RVU24C, RVU24D.
January 1, 2024
RVU24A
$273.19changed to$263.82
- Conversion factor 33.8872 changed to 32.7442
- Practice expense RVU 8.36 changed to 8.20
- Malpractice RVU 0.06 changed to 0.09
- Practice expense GPCI 0.893 changed to 0.908
- Malpractice GPCI 0.439 changed to 0.461
January 1, 2023
RVU23A
$278.71changed to$273.19
- Conversion factor 34.6062 changed to 33.8872
- Practice expense RVU 8.50 changed to 8.36
- Malpractice RVU 0.07 changed to 0.06
- Practice expense GPCI 0.877 changed to 0.893
- Malpractice GPCI 0.416 changed to 0.439
Held through RVU23B, RVU23C, RVU23D.
January 1, 2022
RVU22A
$292.64changed to$278.71
- Conversion factor 34.8931 changed to 34.6062
- Practice expense RVU 8.88 changed to 8.50
Held through RVU22B, RVU22C, RVU22D.
January 1, 2021
RVU21A
$299.26changed to$292.64
- Conversion factor 36.0896 changed to 34.8931
- Practice expense RVU 8.64 changed to 8.88
- Practice expense GPCI 0.890 changed to 0.877
- Malpractice GPCI 0.464 changed to 0.416
Held through RVU21B, RVU21C, RVU21D.
January 1, 2020
RVU20A
$305.62changed to$299.26
- Conversion factor 36.0391 changed to 36.0896
- Practice expense RVU 8.73 changed to 8.64
- Practice expense GPCI 0.902 changed to 0.890
- Malpractice GPCI 0.512 changed to 0.464
Held through RVU20B, RVU20C, RVU20D.
January 1, 2019
RVU19A
$310.81changed to$305.62
- Conversion factor 35.9996 changed to 36.0391
- Practice expense RVU 8.90 changed to 8.73
Held through RVU19B, RVU19C, RVU19D.
January 1, 2018
RVU18AR1
$307.59changed to$310.81
- Conversion factor 35.8887 changed to 35.9996
- Practice expense RVU 8.85 changed to 8.90
- Practice expense GPCI 0.900 changed to 0.902
- Malpractice GPCI 0.510 changed to 0.512
Held through RVU18B, RVU18C, RVU18D.
January 1, 2017
RVU17A
$303.66changed to$307.59
- Conversion factor 35.8043 changed to 35.8887
- Practice expense RVU 8.77 changed to 8.85
- Practice expense GPCI 0.898 changed to 0.900
- Malpractice GPCI 0.508 changed to 0.510
Held through RVU17B, RVU17C, RVU17D.
January 1, 2016
RVU16A
$304.43changed to$303.66
- Conversion factor 35.9335 changed to 35.8043
- Practice expense RVU 8.76 changed to 8.77
Held through RVU16B, RVU16C, RVU16D.
July 1, 2015
RVU15C
$302.92changed to$304.43
- Conversion factor 35.7547 changed to 35.9335
Held through RVU15D.
January 1, 2015
RVU15A
$297.01changed to$302.92
- Conversion factor 35.8228 changed to 35.7547
- Practice expense RVU 8.58 changed to 8.76
- Malpractice RVU 0.06 changed to 0.07
- Practice expense GPCI 0.896 changed to 0.898
- Malpractice GPCI 0.556 changed to 0.508
Held through RVU15B.
January 1, 2014
RVU14A
No ratechanged to$297.01
Held through RVU14B, RVU14C, RVU14D.
January 1, 2013
RVU13AR
Earliest loaded release: No rate
Held through RVU13B, RVU13C, RVU13D.
| Effective from | Office | Facility | CMS release |
|---|---|---|---|
| 2026-10-01 | $262.73 | Not available in this setting | RVU26D |
| 2026-07-01 | $262.73 | Not available in this setting | RVU26C |
| 2026-04-01 | $262.73 | Not available in this setting | RVU26B |
| 2026-01-01 | $262.73 | Not available in this setting | RVU26A |
| 2025-10-01 | $256.06 | Not available in this setting | RVU25D |
| 2025-07-01 | $256.06 | Not available in this setting | RVU25C |
| 2025-04-01 | $256.06 | Not available in this setting | RVU25B |
| 2025-01-01 | $256.06 | Not available in this setting | RVU25A |
| 2024-10-01 | $268.20 | Not available in this setting | RVU24D |
| 2024-07-01 | $268.20 | Not available in this setting | RVU24C |
| 2024-04-01 | $268.20 | Not available in this setting | RVU24B |
| 2024-03-09 | $268.20 | Not available in this setting | RVU24AR |
| 2024-01-01 | $263.82 | Not available in this setting | RVU24A |
| 2023-10-01 | $273.19 | Not available in this setting | RVU23D |
| 2023-07-01 | $273.19 | Not available in this setting | RVU23C |
| 2023-04-01 | $273.19 | Not available in this setting | RVU23B |
| 2023-01-01 | $273.19 | Not available in this setting | RVU23A |
| 2022-10-01 | $278.71 | Not available in this setting | RVU22D |
| 2022-07-01 | $278.71 | Not available in this setting | RVU22C |
| 2022-04-01 | $278.71 | Not available in this setting | RVU22B |
| 2022-01-01 | $278.71 | Not available in this setting | RVU22A |
| 2021-10-01 | $292.64 | Not available in this setting | RVU21D |
| 2021-07-01 | $292.64 | Not available in this setting | RVU21C |
| 2021-04-01 | $292.64 | Not available in this setting | RVU21B |
| 2021-01-01 | $292.64 | Not available in this setting | RVU21A |
| 2020-10-01 | $299.26 | Not available in this setting | RVU20D |
| 2020-07-01 | $299.26 | Not available in this setting | RVU20C |
| 2020-04-01 | $299.26 | Not available in this setting | RVU20B |
| 2020-01-01 | $299.26 | Not available in this setting | RVU20A |
| 2019-10-01 | $305.62 | Not available in this setting | RVU19D |
| 2019-07-01 | $305.62 | Not available in this setting | RVU19C |
| 2019-04-01 | $305.62 | Not available in this setting | RVU19B |
| 2019-01-01 | $305.62 | Not available in this setting | RVU19A |
| 2018-10-01 | $310.81 | Not available in this setting | RVU18D |
| 2018-07-01 | $310.81 | Not available in this setting | RVU18C |
| 2018-04-01 | $310.81 | Not available in this setting | RVU18B |
| 2018-01-01 | $310.81 | Not available in this setting | RVU18AR1 |
| 2017-10-01 | $307.59 | Not available in this setting | RVU17D |
| 2017-07-01 | $307.59 | Not available in this setting | RVU17C |
| 2017-04-01 | $307.59 | Not available in this setting | RVU17B |
| 2017-01-01 | $307.59 | Not available in this setting | RVU17A |
| 2016-10-01 | $303.66 | Not available in this setting | RVU16D |
| 2016-07-01 | $303.66 | Not available in this setting | RVU16C |
| 2016-04-01 | $303.66 | Not available in this setting | RVU16B |
| 2016-01-01 | $303.66 | Not available in this setting | RVU16A |
| 2015-10-01 | $304.43 | Not available in this setting | RVU15D |
| 2015-07-01 | $304.43 | Not available in this setting | RVU15C |
| 2015-04-01 | $302.92 | Not available in this setting | RVU15B |
| 2015-01-01 | $302.92 | Not available in this setting | RVU15A |
| 2014-10-01 | $297.01 | Not available in this setting | RVU14D |
| 2014-07-01 | $297.01 | Not available in this setting | RVU14C |
| 2014-04-01 | $297.01 | Not available in this setting | RVU14B |
| 2014-01-01 | $297.01 | Not available in this setting | RVU14A |
| 2013-10-01 | Additional calculation required | Not available in this setting | RVU13D |
| 2013-07-01 | Additional calculation required | Not available in this setting | RVU13C |
| 2013-04-01 | Additional calculation required | Not available in this setting | RVU13B |
| 2013-01-01 | Additional calculation required | Not available in this setting | RVU13AR |
Where the Idaho rate applies
Idaho is a Medicare payment area, not a city. Our Census mapping connects it to 235 cities and communities in Idaho. Some span more than one payment area; confirm with the service ZIP.
- Aberdeen
- Acequia
- Albion
- American Falls
- Ammon
- Arbon Valley
- Arco
- Arimo
78645 billing questions
When should I report 78645 instead of a CSF cisternography code?
Report 78645 when the imaging evaluates flow through an implanted CSF shunt. Cisternography evaluates CSF circulation rather than shunt patency.
How do I report the professional and technical portions?
Use modifier 26 for the professional interpretation and modifier TC for the technical service. Without either modifier, the claim represents the global service.
What documentation supports 78645?
Document the suspected shunt problem, the shunt evaluated, radiotracer administration, the imaging performed, and the interpreting clinician’s findings about tracer progression.
Is this the right code for locating a CSF leak?
No. 78645 evaluates an implanted shunt; code 78650 is associated with CSF leak 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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