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CPT code 77338: MLC design, per IMRT plan2026 Medicare rate & RVUs in Connecticut

Reports design of multileaf collimator devices that shape radiation fields for intensity-modulated radiation therapy, counted per IMRT plan.

CMS RVU26DEffective Oct 1, 2026One payment locality211.7K Medicare services in 2024

In Connecticut, Medicare pays $504.69 for 77338 in the office.

$504.69Office (non-facility)
Not available in this settingHospital or facility
+6.3%vs the national office rate ($474.96)

Check a contract rate as a % of Medicare · 77338 nationwide

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

We’ll open 77338 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in Connecticut
  2. What 77338 covers
  3. Compared with other areas
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Related codes
  8. Rate history
  9. Where it applies
  10. Billing questions
  11. Sources

What 77338 covers

This service covers planning the multileaf collimator (MLC) leaf positions needed to shape and modulate radiation fields for an intensity-modulated radiation therapy (IMRT) plan. A medical physicist or dosimetrist typically performs the technical design work as part of radiation treatment planning, with the radiation oncologist directing the treatment approach. The work supports delivery of the planned dose to the target while shaping radiation around nearby normal tissues.

Report the service per IMRT plan, not per treatment fraction. Documentation should connect the MLC design to the specific IMRT plan and identify the design work performed. CMS recognizes professional and technical components: modifier 26 identifies the professional component, modifier TC identifies the technical component, and an unmodified claim represents the global service. The IMRT dose plan itself is reported separately when supported; MLC device design is distinct from dose calculation and from design of other treatment aids.

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 Connecticut compares for 77338

Across 109 of 109 payment localities, the office rate for 77338 runs from $424.80 in Arkansas to $630.98 in San Benito County, CA. Connecticut pays $504.69. The RVUs are the same everywhere; the geographic indexes change the dollars.

77338 in Connecticut vs other payment areas
  1. Connecticut · this page$504.69
  2. Los Angeles, CA · California$537.72+$33.03
  3. Washington, DC area · District of Columbia$541.65+$36.96
  4. Miami, FL · Florida$501.14−$3.55
  5. Chicago, IL · Illinois$488.39−$16.30
  6. Manhattan, NY · New York$541.76+$37.07
  7. Alaska · Alaska$562.27+$57.58

Other areas in Connecticut first, then benchmark localities. Bars start at $0.

Every other payment area

77338 in every other Medicare payment locality
Payment localityOfficeFacility
AlabamaAlabama$430.46—
ArkansasArkansas$424.80—
ArizonaArizona$463.62—
Bakersfield, CACalifornia$505.74—
Chico, CACalifornia$504.85—
El Centro, CACalifornia$504.89—
Fresno, CACalifornia$504.85—
Hanford, CACalifornia$504.85—

77338 rates by state

Office rate range in each state. Select a state to see its payment localities.

MEWIVTNHMTNDMNMINYMARIWAIDWYSDIAILINOHPANJCTORNVUTCONEMOKYWVVAMDDECAAZNMKSOKARTNNCSCDCTXLAMSALGAFLAKHI

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.

$424.80

$567.92

Color shows the midpoint of each state’s locality range.

View every state and territory as a table
77338 office rate range by state
State / territoryOffice rate rangeLocalities
AK$562.271
AL$430.461
AR$424.801
AZ$463.621
CA$504.85–$630.9829
CO$495.741
CT$504.691
DC$541.651
DE$470.891
FL$464.77–$501.143
GA$441.25–$482.292
GU$516.241
HI$516.241
IA$442.131
ID$444.401
IL$451.21–$491.214
IN$446.801
KS$439.431
KY$437.951
LA$437.01–$456.802
MA$492.83–$543.202
MD$479.60–$541.653
ME$445.64–$468.942
MI$447.59–$469.242
MN$478.571
MO$429.62–$459.283
MS$427.331
MT$474.941
NC$450.041
ND$470.001
NE$444.591
NH$487.321
NJ$511.44–$536.642
NM$449.501
NV$473.891
NY$456.13–$552.855
OH$446.581
OK$438.111
OR$471.17–$511.352
PA$447.69–$492.492
PR$478.431
RI$487.501
SC$448.861
SD$469.421
TN$441.341
TX$444.94–$493.258
UT$454.491
VA$466.95–$541.652
VI$478.431
VT$467.571
WA$492.11–$554.642
WI$455.451
WV$435.721
WY$472.791

See 77338 in every payment locality

How the 77338 rate is calculated

Each of 77338’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 · 77338

RVUs × geographic indexes × conversion factor

Office or facility?

Work4.18

4.18 RVUs× 1.000 GPCI

Practice expense9.79

9.79 RVUs× 1.000 GPCI

Malpractice0.25

0.25 RVUs× 1.000 GPCI

Adjusted RVUs

14.2200

Conversion factor

$33.4009

Medicare rate

$474.96

Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.

The exact Connecticut inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

9,084

Code
77338
Physician work
4.18
Practice expense
9.79
Malpractice
0.25

GPCI2026.csv

38

Locality
Connecticut
Physician work
1.020
Practice expense
1.077
Malpractice
1.210
Office calculation for 77338 in Connecticut
ComponentRVULocality factorAdjusted
Physician work4.18× 1.0204.2636
Practice expense9.79× 1.07710.5438
Malpractice0.25× 1.2100.3025
Total RVUs15.1099
Conversion factor× 33.4009

Office rate, Connecticut$504.69

Office: (4.18 × 1.02 + 9.79 × 1.077 + 0.25 × 1.21) × $33.4009 = $504.69

Open 77338 in the RVU calculator

Payment rules and modifiers for 77338

The CMS indicators that decide how 77338 is paid alongside other services.

CMS payment indicators · 77338

MLC design, per IMRT plan

RuleCMS valueWhat it means
Global periodXXXThe global surgery concept doesn’t apply.
Multiple procedures0No multiple-procedure reduction.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)0Not paid without supporting documentation.
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical1Diagnostic test with separate professional (26) and technical (TC) components.

What modifiers do to the payment

Modifier 26 · payment effect

With and without the modifier

77338 without 26 · national office

$474.96

MLC design, per IMRT plan

77338-26 · Professional component

$225.12

Pays only the interpretation and report.

When to use modifier 26

Codes related to 77338

Related codes aren’t interchangeable: bill the code that matches the service performed.

Codes related to 77338
CodeHow it relatesOffice range, Connecticut
Often billed with
77301IMRT planning, dose optimization and volume analysisRepresents IMRT dose planning, commonly associated with the MLC design for the same plan.$2,099.52
Used instead
77306Radiation plan, simple teletherapy planSimple teletherapy isodose planning may be used for a conventional plan instead of IMRT planning.$159.62
77307Isodose planning, complex teletherapy planComplex teletherapy isodose planning is a conventional planning approach rather than IMRT MLC design.$307.93

How 77338 has changed in Connecticut

77338 · Office / nonfacility

$504.69

Effective 2026-10-01

The base rate is $9.74 higher than on 2025-10-01, moving from $494.95 to $504.69 (2.0%).

It is unchanged from the immediately preceding available release, effective 2026-07-01.

Base rate by release · bars start at $0 · select a bar to compare

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

  1. January 1, 2026

    RVU26A

    $494.95changed to$504.69

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 4.29 changed to 4.18
    • Practice expense RVU 9.73 changed to 9.79
    • Work GPCI 1.022 changed to 1.020
    • Practice expense GPCI 1.091 changed to 1.077
    • Malpractice GPCI 1.207 changed to 1.210

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $501.80changed to$494.95

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 9.50 changed to 9.73
    • Malpractice RVU 0.27 changed to 0.25

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $493.61changed to$501.80

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $506.83changed to$493.61

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 9.31 changed to 9.50
    • Malpractice RVU 0.26 changed to 0.27
    • Work GPCI 1.030 changed to 1.022
    • Practice expense GPCI 1.102 changed to 1.091
    • Malpractice GPCI 1.070 changed to 1.207

  5. January 1, 2023

    RVU23A

    $506.24changed to$506.83

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 8.92 changed to 9.31
    • Work GPCI 1.037 changed to 1.030
    • Practice expense GPCI 1.114 changed to 1.102
    • Malpractice GPCI 0.934 changed to 1.070

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $522.41changed to$506.24

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 9.27 changed to 8.92
    • Malpractice RVU 0.21 changed to 0.26

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $540.35changed to$522.41

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 9.26 changed to 9.27
    • Malpractice RVU 0.23 changed to 0.21
    • Work GPCI 1.029 changed to 1.037
    • Practice expense GPCI 1.113 changed to 1.114
    • Malpractice GPCI 1.094 changed to 0.934

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $554.64changed to$540.35

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 9.63 changed to 9.26
    • Malpractice RVU 0.24 changed to 0.23
    • Work GPCI 1.021 changed to 1.029
    • Practice expense GPCI 1.112 changed to 1.113
    • Malpractice GPCI 1.255 changed to 1.094

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $573.64changed to$554.64

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 10.12 changed to 9.63

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $563.88changed to$573.64

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 9.87 changed to 10.12
    • Work GPCI 1.023 changed to 1.021
    • Practice expense GPCI 1.117 changed to 1.112
    • Malpractice GPCI 1.244 changed to 1.255

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $561.61changed to$563.88

    • Conversion factor 35.8043 changed to 35.8887
    • Practice expense RVU 9.81 changed to 9.87
    • Work GPCI 1.024 changed to 1.023
    • Practice expense GPCI 1.121 changed to 1.117
    • Malpractice GPCI 1.232 changed to 1.244

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $556.07changed to$561.61

    • Conversion factor 35.9335 changed to 35.8043
    • Practice expense RVU 9.60 changed to 9.81
    • Malpractice RVU 0.26 changed to 0.24

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $553.30changed to$556.07

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $547.06changed to$553.30

    • Conversion factor 35.8228 changed to 35.7547
    • Practice expense RVU 9.46 changed to 9.60
    • Practice expense GPCI 1.116 changed to 1.121
    • Malpractice GPCI 1.234 changed to 1.232

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    $544.88changed to$547.06

    • Conversion factor 34.0230 changed to 35.8228
    • Practice expense RVU 10.17 changed to 9.46
    • Malpractice RVU 0.27 changed to 0.26
    • Practice expense GPCI 1.110 changed to 1.116
    • Malpractice GPCI 1.235 changed to 1.234

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: $544.88

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$504.69Not available in this settingRVU26D
2026-07-01$504.69Not available in this settingRVU26C
2026-04-01$504.69Not available in this settingRVU26B
2026-01-01$504.69Not available in this settingRVU26A
2025-10-01$494.95Not available in this settingRVU25D
2025-07-01$494.95Not available in this settingRVU25C
2025-04-01$494.95Not available in this settingRVU25B
2025-01-01$494.95Not available in this settingRVU25A
2024-10-01$501.80Not available in this settingRVU24D
2024-07-01$501.80Not available in this settingRVU24C
2024-04-01$501.80Not available in this settingRVU24B
2024-03-09$501.80Not available in this settingRVU24AR
2024-01-01$493.61Not available in this settingRVU24A
2023-10-01$506.83Not available in this settingRVU23D
2023-07-01$506.83Not available in this settingRVU23C
2023-04-01$506.83Not available in this settingRVU23B
2023-01-01$506.83Not available in this settingRVU23A
2022-10-01$506.24Not available in this settingRVU22D
2022-07-01$506.24Not available in this settingRVU22C
2022-04-01$506.24Not available in this settingRVU22B
2022-01-01$506.24Not available in this settingRVU22A
2021-10-01$522.41Not available in this settingRVU21D
2021-07-01$522.41Not available in this settingRVU21C
2021-04-01$522.41Not available in this settingRVU21B
2021-01-01$522.41Not available in this settingRVU21A
2020-10-01$540.35Not available in this settingRVU20D
2020-07-01$540.35Not available in this settingRVU20C
2020-04-01$540.35Not available in this settingRVU20B
2020-01-01$540.35Not available in this settingRVU20A
2019-10-01$554.64Not available in this settingRVU19D
2019-07-01$554.64Not available in this settingRVU19C
2019-04-01$554.64Not available in this settingRVU19B
2019-01-01$554.64Not available in this settingRVU19A
2018-10-01$573.64Not available in this settingRVU18D
2018-07-01$573.64Not available in this settingRVU18C
2018-04-01$573.64Not available in this settingRVU18B
2018-01-01$573.64Not available in this settingRVU18AR1
2017-10-01$563.88Not available in this settingRVU17D
2017-07-01$563.88Not available in this settingRVU17C
2017-04-01$563.88Not available in this settingRVU17B
2017-01-01$563.88Not available in this settingRVU17A
2016-10-01$561.61Not available in this settingRVU16D
2016-07-01$561.61Not available in this settingRVU16C
2016-04-01$561.61Not available in this settingRVU16B
2016-01-01$561.61Not available in this settingRVU16A
2015-10-01$556.07Not available in this settingRVU15D
2015-07-01$556.07Not available in this settingRVU15C
2015-04-01$553.30Not available in this settingRVU15B
2015-01-01$553.30Not available in this settingRVU15A
2014-10-01$547.06Not available in this settingRVU14D
2014-07-01$547.06Not available in this settingRVU14C
2014-04-01$547.06Not available in this settingRVU14B
2014-01-01$547.06Not available in this settingRVU14A
2013-10-01$544.88Not available in this settingRVU13D
2013-07-01$544.88Not available in this settingRVU13C
2013-04-01$544.88Not available in this settingRVU13B
2013-01-01$544.88Not available in this settingRVU13AR

Price 77338 for an earlier date of service

Where the Connecticut rate applies

Connecticut is a Medicare payment area, not a city. Our Census mapping connects it to 215 cities and communities in Connecticut. Some span more than one payment area; confirm with the service ZIP.

  • Ansonia
  • Ball Pond
  • Baltic
  • Bantam
  • Bethel
  • Bethlehem Village
  • Bigelow Corners
  • Blue Hills

Browse all communities in Connecticut

77338 billing questions

How is 77338 distinguished from 77301?

77338 represents the MLC device design for an IMRT plan. 77301 represents the IMRT treatment planning work, including the dose plan; the services describe different parts of planning.

Is 77338 reported per treatment fraction or per plan?

Report it per IMRT plan, rather than once for each delivered fraction.

Which modifier identifies each component?

Use modifier 26 for the professional component and modifier TC for the technical component. Submit without a component modifier for the global service.

Does 77338 include the IMRT dose calculation?

No. It describes MLC device design; the dose-planning work is represented separately when applicable and documented.

What documentation supports 77338?

The record should identify the IMRT plan and show the MLC design work performed for that plan. It should support the per-plan unit reported.

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
RVUs for 77338PPRRVU2026_Oct_nonQPP.csv, line 9,084 (RVU26D)
Geographic factors for ConnecticutGPCI2026.csv, line 38 (RVU26D)

Open CMS sourceHow we calculate rates

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