CPT code 77331: Radiation dosimetry, special measurement2026 Medicare rate & RVUs in Vermont
Reports specialized radiation dose measurement, such as TLD-based dosimetry, when a radiation oncology team needs more than routine treatment-planning calculations.
In Vermont, Medicare pays $63.96 for 77331 in the office.
Check a contract rate as a % of Medicare · 77331 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 77331 covers
This service covers specialized measurement of radiation dose, including methods such as thermoluminescent dosimetry (TLD) or microdosimetry. A radiation oncology physicist typically performs or interprets the work, with technical staff and measurement equipment supporting the test. It may be used when the team needs a patient-specific dose measurement or verification beyond routine dose calculations in a radiation treatment plan.
Select the code for the specialized measurement actually performed, not simply because a treatment plan includes dose calculations. Documentation should identify the measurement method, its clinical purpose, and the findings or interpretation. CMS treats the service as having professional and technical components: report modifier 26 for the interpretation, modifier TC for the equipment and staff, or neither modifier when billing the global service. The record should support the component billed and show that the specialized measurement was performed.
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 Vermont compares for 77331
Across 109 of 109 payment localities, the office rate for 77331 runs from $59.38 in Arkansas to $82.98 in San Benito County, CA. Vermont pays $63.96. The RVUs are the same everywhere; the geographic indexes change the dollars.
- Vermont · this page$63.96
- Los Angeles, CA · California$72.15+$8.19
- Washington, DC area · District of Columbia$73.10+$9.14
- Miami, FL · Florida$69.12+$5.16
- Chicago, IL · Illinois$67.67+$3.71
- Manhattan, NY · New York$73.61+$9.65
- Alaska · Alaska$80.86+$16.90
Other areas in Vermont first, then benchmark localities. Bars start at $0.
Every other payment area
| Payment locality | Office | Facility |
|---|---|---|
| AlabamaAlabama | $60.02 | — |
| ArkansasArkansas | $59.38 | — |
| ArizonaArizona | $63.80 | — |
| Bakersfield, CACalifornia | $68.39 | — |
| Chico, CACalifornia | $68.21 | — |
| El Centro, CACalifornia | $68.21 | — |
| Fresno, CACalifornia | $68.21 | — |
| Hanford, CACalifornia | $68.21 | — |
| Madera, CACalifornia | $68.21 | — |
| Merced, CACalifornia | $68.21 | — |
| Modesto, CACalifornia | $68.21 | — |
| Napa, CACalifornia | $77.25 | — |
| Oxnard, CACalifornia | $71.68 | — |
| Redding, CACalifornia | $68.21 | — |
| Rest of CaliforniaCalifornia | $68.21 | — |
| Riverside, CACalifornia | $68.76 | — |
| Sacramento, CACalifornia | $71.10 | — |
| Salinas, CACalifornia | $70.81 | — |
| San Diego, CACalifornia | $72.09 | — |
| Marin County, CACalifornia | $81.30 | — |
| San Francisco, CACalifornia | $81.25 | — |
| San Benito County, CACalifornia | $82.98 | — |
| Santa Clara County, CACalifornia | $82.75 | — |
| San Luis Obispo, CACalifornia | $69.71 | — |
| Santa Cruz, CACalifornia | $72.49 | — |
| Santa Maria, CACalifornia | $70.97 | — |
| Santa Rosa, CACalifornia | $73.20 | — |
| Stockton, CACalifornia | $68.21 | — |
| Vallejo, CACalifornia | $77.17 | — |
| Visalia, CACalifornia | $68.21 | — |
| Yuba City, CACalifornia | $68.21 | — |
| ColoradoColorado | $67.35 | — |
| ConnecticutConnecticut | $68.75 | — |
| DelawareDelaware | $64.68 | — |
| Fort Lauderdale, FLFlorida | $66.94 | — |
| Rest of FloridaFlorida | $64.43 | — |
| Atlanta, GAGeorgia | $66.11 | — |
| Rest of GeorgiaGeorgia | $61.66 | — |
| Hawaii, Guam, HIHawaii | $69.23 | — |
| IowaIowa | $61.14 | — |
| IdahoIdaho | $61.45 | — |
| East St. Louis, ILIllinois | $64.02 | — |
| Rest of IllinoisIllinois | $63.02 | — |
| Suburban Chicago, ILIllinois | $67.57 | — |
| IndianaIndiana | $61.71 | — |
| KansasKansas | $60.94 | — |
| KentuckyKentucky | $61.10 | — |
| New Orleans, LALouisiana | $63.29 | — |
| Rest of LouisianaLouisiana | $61.03 | — |
| Metropolitan Boston, MAMassachusetts | $72.92 | — |
| Rest of MassachusettsMassachusetts | $67.11 | — |
| Baltimore area, MDMaryland | $68.54 | — |
| Rest of MarylandMaryland | $65.70 | — |
| Rest of MaineMaine | $61.69 | — |
| Southern Maine, MEMaine | $64.20 | — |
| Detroit, MIMichigan | $65.05 | — |
| Rest of MichiganMichigan | $62.30 | — |
| MinnesotaMinnesota | $64.97 | — |
| Metropolitan Kansas City, MOMissouri | $62.95 | — |
| Metropolitan St. Louis, MOMissouri | $63.45 | — |
| Rest of MissouriMissouri | $60.25 | — |
| MississippiMississippi | $59.82 | — |
| MontanaMontana | $65.13 | — |
| North CarolinaNorth Carolina | $62.18 | — |
| North DakotaNorth Dakota | $64.14 | — |
| NebraskaNebraska | $61.39 | — |
| New HampshireNew Hampshire | $66.36 | — |
| Northern New JerseyNew Jersey | $72.65 | — |
| Rest of New JerseyNew Jersey | $69.66 | — |
| New MexicoNew Mexico | $62.56 | — |
| NevadaNevada | $64.89 | — |
| NYC suburbs and Long Island, NYNew York | $75.01 | — |
| Poughkeepsie and northern NYC suburbs, NYNew York | $70.09 | — |
| Queens, NYNew York | $74.07 | — |
| Rest of New YorkNew York | $62.88 | — |
| OhioOhio | $62.09 | — |
| OklahomaOklahoma | $61.01 | — |
| Portland, OROregon | $69.05 | — |
| Rest of OregonOregon | $64.50 | — |
| Metropolitan Philadelphia, PAPennsylvania | $67.40 | — |
| Rest of PennsylvaniaPennsylvania | $62.16 | — |
| Puerto RicoPuerto Rico | $65.49 | — |
| Rhode IslandRhode Island | $66.65 | — |
| South CarolinaSouth Carolina | $62.22 | — |
| South DakotaSouth Dakota | $64.02 | — |
| TennesseeTennessee | $61.17 | — |
| Austin, TXTexas | $67.03 | — |
| Beaumont, TXTexas | $61.86 | — |
| Brazoria, TXTexas | $64.68 | — |
| Dallas, TXTexas | $65.01 | — |
| Fort Worth, TXTexas | $64.68 | — |
| Galveston, TXTexas | $64.83 | — |
| Houston, TXTexas | $65.74 | — |
| Rest of TexasTexas | $63.18 | — |
| UtahUtah | $62.86 | — |
| VirginiaVirginia | $64.04 | — |
| Virgin Islands, VIUnited States Virgin Islands | $65.49 | — |
| Rest of WashingtonWashington | $66.96 | — |
| King County, WAWashington | $74.21 | — |
| WisconsinWisconsin | $62.50 | — |
| West VirginiaWest Virginia | $61.26 | — |
| WyomingWyoming | $64.70 | — |
77331 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.
$59.38
$80.86
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 | $80.86 | 1 |
| AL | $60.02 | 1 |
| AR | $59.38 | 1 |
| AZ | $63.80 | 1 |
| CA | $68.21–$82.98 | 29 |
| CO | $67.35 | 1 |
| CT | $68.75 | 1 |
| DC | $73.10 | 1 |
| DE | $64.68 | 1 |
| FL | $64.43–$69.12 | 3 |
| GA | $61.66–$66.11 | 2 |
| GU | $69.23 | 1 |
| HI | $69.23 | 1 |
| IA | $61.14 | 1 |
| ID | $61.45 | 1 |
| IL | $63.02–$67.67 | 4 |
| IN | $61.71 | 1 |
| KS | $60.94 | 1 |
| KY | $61.10 | 1 |
| LA | $61.03–$63.29 | 2 |
| MA | $67.11–$72.92 | 2 |
| MD | $65.70–$73.10 | 3 |
| ME | $61.69–$64.20 | 2 |
| MI | $62.30–$65.05 | 2 |
| MN | $64.97 | 1 |
| MO | $60.25–$63.45 | 3 |
| MS | $59.82 | 1 |
| MT | $65.13 | 1 |
| NC | $62.18 | 1 |
| ND | $64.14 | 1 |
| NE | $61.39 | 1 |
| NH | $66.36 | 1 |
| NJ | $69.66–$72.65 | 2 |
| NM | $62.56 | 1 |
| NV | $64.89 | 1 |
| NY | $62.88–$75.01 | 5 |
| OH | $62.09 | 1 |
| OK | $61.01 | 1 |
| OR | $64.50–$69.05 | 2 |
| PA | $62.16–$67.40 | 2 |
| PR | $65.49 | 1 |
| RI | $66.65 | 1 |
| SC | $62.22 | 1 |
| SD | $64.02 | 1 |
| TN | $61.17 | 1 |
| TX | $61.86–$67.03 | 8 |
| UT | $62.86 | 1 |
| VA | $64.04–$73.10 | 2 |
| VI | $65.49 | 1 |
| VT | $63.96 | 1 |
| WA | $66.96–$74.21 | 2 |
| WI | $62.50 | 1 |
| WV | $61.26 | 1 |
| WY | $64.70 | 1 |
How the 77331 rate is calculated
Each of 77331’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 · 77331
RVUs × geographic indexes × conversion factor
Work0.85
0.85 RVUs× 1.000 GPCI
Practice expense1.05
1.05 RVUs× 1.000 GPCI
Malpractice0.05
0.05 RVUs× 1.000 GPCI
Adjusted RVUs
1.9500
Conversion factor
$33.4009
Medicare rate
$65.13
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
The exact Vermont inputs and CMS source lines
PPRRVU2026_Oct_nonQPP.csv
9,071
- Code
- 77331
- Physician work
- 0.85
- Practice expense
- 1.05
- Malpractice
- 0.05
GPCI2026.csv
105
- Locality
- Vermont
- Physician work
- 1.000
- Practice expense
- 0.990
- Malpractice
- 0.506
| Component | RVU | Locality factor | Adjusted |
|---|---|---|---|
| Physician work | 0.85 | × 1.000 | 0.8500 |
| Practice expense | 1.05 | × 0.990 | 1.0395 |
| Malpractice | 0.05 | × 0.506 | 0.0253 |
| Total RVUs | 1.9148 | ||
| Conversion factor | × 33.4009 | ||
Office rate, Vermont$63.96
Office: (0.85 × 1 + 1.05 × 0.99 + 0.05 × 0.506) × $33.4009 = $63.96
Payment rules and modifiers for 77331
The CMS indicators that decide how 77331 is paid alongside other services.
CMS payment indicators · 77331
Radiation dosimetry, special measurement
| 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
77331 without 26 · national office
$65.13
Radiation dosimetry, special measurement
77331-26 · Professional component
$45.76
Pays only the interpretation and report.
How 77331 has changed in Vermont
77331 · Office / nonfacility
$63.96
Effective 2026-10-01
The base rate is $1.25 higher than on 2025-10-01, moving from $62.71 to $63.96 (2.0%).
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
$62.71changed to$63.96
- Conversion factor 32.3465 changed to 33.4009
- Work RVU 0.87 changed to 0.85
- Practice expense GPCI 0.993 changed to 0.990
- Malpractice GPCI 0.518 changed to 0.506
Held through RVU26B, RVU26C, RVU26D.
January 1, 2025
RVU25A
$63.87changed to$62.71
- Conversion factor 33.2875 changed to 32.3465
- Practice expense RVU 1.03 changed to 1.05
Held through RVU25B, RVU25C, RVU25D.
March 9, 2024
RVU24AR
$62.83changed to$63.87
- Conversion factor 32.7442 changed to 33.2875
Held through RVU24B, RVU24C, RVU24D.
January 1, 2024
RVU24A
$64.53changed to$62.83
- Conversion factor 33.8872 changed to 32.7442
- Practice expense RVU 1.01 changed to 1.03
- Practice expense GPCI 0.997 changed to 0.993
- Malpractice GPCI 0.543 changed to 0.518
January 1, 2023
RVU23A
$64.69changed to$64.53
- Conversion factor 34.6062 changed to 33.8872
- Practice expense RVU 0.97 changed to 1.01
- Practice expense GPCI 1.001 changed to 0.997
- Malpractice GPCI 0.569 changed to 0.543
Held through RVU23B, RVU23C, RVU23D.
January 1, 2022
RVU22A
$65.23changed to$64.69
- Conversion factor 34.8931 changed to 34.6062
Held through RVU22B, RVU22C, RVU22D.
January 1, 2021
RVU21A
$66.07changed to$65.23
- Conversion factor 36.0896 changed to 34.8931
- Practice expense RVU 0.93 changed to 0.97
- Malpractice RVU 0.04 changed to 0.05
- Practice expense GPCI 1.008 changed to 1.001
- Malpractice GPCI 0.582 changed to 0.569
Held through RVU21B, RVU21C, RVU21D.
January 1, 2020
RVU20A
$66.08changed to$66.07
- Conversion factor 36.0391 changed to 36.0896
- Practice expense RVU 0.92 changed to 0.93
- Malpractice RVU 0.05 changed to 0.04
- Practice expense GPCI 1.015 changed to 1.008
- Malpractice GPCI 0.595 changed to 0.582
Held through RVU20B, RVU20C, RVU20D.
January 1, 2019
RVU19A
$66.01changed to$66.08
- Conversion factor 35.9996 changed to 36.0391
Held through RVU19B, RVU19C, RVU19D.
January 1, 2018
RVU18AR1
$64.99changed to$66.01
- Conversion factor 35.8887 changed to 35.9996
- Practice expense RVU 0.90 changed to 0.92
- Practice expense GPCI 1.010 changed to 1.015
- Malpractice GPCI 0.639 changed to 0.595
Held through RVU18B, RVU18C, RVU18D.
January 1, 2017
RVU17A
$64.00changed to$64.99
- Conversion factor 35.8043 changed to 35.8887
- Practice expense RVU 0.88 changed to 0.90
- Practice expense GPCI 1.004 changed to 1.010
- Malpractice GPCI 0.682 changed to 0.639
Held through RVU17B, RVU17C, RVU17D.
January 1, 2016
RVU16A
$63.87changed to$64.00
- Conversion factor 35.9335 changed to 35.8043
- Practice expense RVU 0.87 changed to 0.88
Held through RVU16B, RVU16C, RVU16D.
July 1, 2015
RVU15C
$63.56changed to$63.87
- Conversion factor 35.7547 changed to 35.9335
Held through RVU15D.
January 1, 2015
RVU15A
$63.27changed to$63.56
- Conversion factor 35.8228 changed to 35.7547
- Practice expense RVU 0.86 changed to 0.87
- Practice expense GPCI 1.006 changed to 1.004
- Malpractice GPCI 0.618 changed to 0.682
Held through RVU15B.
January 1, 2014
RVU14A
No ratechanged to$63.27
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 | $63.96 | Not available in this setting | RVU26D |
| 2026-07-01 | $63.96 | Not available in this setting | RVU26C |
| 2026-04-01 | $63.96 | Not available in this setting | RVU26B |
| 2026-01-01 | $63.96 | Not available in this setting | RVU26A |
| 2025-10-01 | $62.71 | Not available in this setting | RVU25D |
| 2025-07-01 | $62.71 | Not available in this setting | RVU25C |
| 2025-04-01 | $62.71 | Not available in this setting | RVU25B |
| 2025-01-01 | $62.71 | Not available in this setting | RVU25A |
| 2024-10-01 | $63.87 | Not available in this setting | RVU24D |
| 2024-07-01 | $63.87 | Not available in this setting | RVU24C |
| 2024-04-01 | $63.87 | Not available in this setting | RVU24B |
| 2024-03-09 | $63.87 | Not available in this setting | RVU24AR |
| 2024-01-01 | $62.83 | Not available in this setting | RVU24A |
| 2023-10-01 | $64.53 | Not available in this setting | RVU23D |
| 2023-07-01 | $64.53 | Not available in this setting | RVU23C |
| 2023-04-01 | $64.53 | Not available in this setting | RVU23B |
| 2023-01-01 | $64.53 | Not available in this setting | RVU23A |
| 2022-10-01 | $64.69 | Not available in this setting | RVU22D |
| 2022-07-01 | $64.69 | Not available in this setting | RVU22C |
| 2022-04-01 | $64.69 | Not available in this setting | RVU22B |
| 2022-01-01 | $64.69 | Not available in this setting | RVU22A |
| 2021-10-01 | $65.23 | Not available in this setting | RVU21D |
| 2021-07-01 | $65.23 | Not available in this setting | RVU21C |
| 2021-04-01 | $65.23 | Not available in this setting | RVU21B |
| 2021-01-01 | $65.23 | Not available in this setting | RVU21A |
| 2020-10-01 | $66.07 | Not available in this setting | RVU20D |
| 2020-07-01 | $66.07 | Not available in this setting | RVU20C |
| 2020-04-01 | $66.07 | Not available in this setting | RVU20B |
| 2020-01-01 | $66.07 | Not available in this setting | RVU20A |
| 2019-10-01 | $66.08 | Not available in this setting | RVU19D |
| 2019-07-01 | $66.08 | Not available in this setting | RVU19C |
| 2019-04-01 | $66.08 | Not available in this setting | RVU19B |
| 2019-01-01 | $66.08 | Not available in this setting | RVU19A |
| 2018-10-01 | $66.01 | Not available in this setting | RVU18D |
| 2018-07-01 | $66.01 | Not available in this setting | RVU18C |
| 2018-04-01 | $66.01 | Not available in this setting | RVU18B |
| 2018-01-01 | $66.01 | Not available in this setting | RVU18AR1 |
| 2017-10-01 | $64.99 | Not available in this setting | RVU17D |
| 2017-07-01 | $64.99 | Not available in this setting | RVU17C |
| 2017-04-01 | $64.99 | Not available in this setting | RVU17B |
| 2017-01-01 | $64.99 | Not available in this setting | RVU17A |
| 2016-10-01 | $64.00 | Not available in this setting | RVU16D |
| 2016-07-01 | $64.00 | Not available in this setting | RVU16C |
| 2016-04-01 | $64.00 | Not available in this setting | RVU16B |
| 2016-01-01 | $64.00 | Not available in this setting | RVU16A |
| 2015-10-01 | $63.87 | Not available in this setting | RVU15D |
| 2015-07-01 | $63.87 | Not available in this setting | RVU15C |
| 2015-04-01 | $63.56 | Not available in this setting | RVU15B |
| 2015-01-01 | $63.56 | Not available in this setting | RVU15A |
| 2014-10-01 | $63.27 | Not available in this setting | RVU14D |
| 2014-07-01 | $63.27 | Not available in this setting | RVU14C |
| 2014-04-01 | $63.27 | Not available in this setting | RVU14B |
| 2014-01-01 | $63.27 | Not available in this setting | RVU14A |
| 2013-10-01 | Rate data unavailable | Not available in this setting | RVU13D |
| 2013-07-01 | Rate data unavailable | Not available in this setting | RVU13C |
| 2013-04-01 | Rate data unavailable | Not available in this setting | RVU13B |
| 2013-01-01 | Rate data unavailable | Not available in this setting | RVU13AR |
Where the Vermont rate applies
Vermont is a Medicare payment area, not a city. Our Census mapping connects it to 180 cities and communities in Vermont. Some span more than one payment area; confirm with the service ZIP.
- Albany
- Alburgh
- Algiers
- Arlington
- Ascutney
- Bakersfield
- Barnet
- Barre
77331 billing questions
How is this different from 77300?
Use 77300 for routine radiation dose calculations. Report 77331 when specialized measurement, such as TLD or microdosimetry, is performed rather than relying only on those calculations.
Which modifier identifies the interpretation?
Append modifier 26 for the professional interpretation. Modifier TC identifies the technical component, including equipment and staff; billing without either modifier represents the global service.
What documentation supports reporting 77331?
Document the specialized measurement method, why it was needed, and the measured results or interpretation. The record should make clear that the work was more than routine treatment-planning calculation.
Can 77331 be reported with a radiation dose plan?
It may accompany a dose-planning service when the specialized measurement is a distinct service actually performed. The record should distinguish the measurement from the plan's routine calculations.
Does this code describe a radiation treatment aid?
No. It describes specialized dose measurement; codes 77332–77334 describe radiation treatment aids, such as devices used to shape or support treatment delivery.
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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