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CPT code 45331: Sigmoidoscopy, with biopsy2026 Medicare rate & RVUs in Metropolitan Boston, MA

Reports flexible sigmoidoscopy with one or more tissue biopsies when a clinician samples the rectum or distal colon for diagnosis.

CMS RVU26DEffective Oct 1, 2026One payment locality35.9K Medicare services in 2024

In Metropolitan Boston, MA, Medicare pays $378.55 for 45331 in the office and $72.67 when it’s performed in a hospital or facility.

$378.55Office (non-facility)
$72.67Hospital or facility
+17.2%vs the national office rate ($322.99)

Check a contract rate as a % of Medicare · 45331 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 45331 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in Metropolitan Boston, MA
  2. What 45331 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 45331 covers

A clinician advances a flexible endoscope through the anus to examine the rectum and distal colon, then collects mucosal tissue for analysis. Gastroenterologists and colorectal surgeons commonly perform this service in an endoscopy unit, hospital outpatient department, or office. Typical reasons include evaluating suspected colitis, unexplained rectal bleeding, or an abnormality seen on prior testing. The biopsy may involve one or multiple tissue samples during the same examination.

Report this code when the procedure includes tissue biopsy, rather than inspection alone; the number of samples does not determine separate units. The record should identify the sampled site and clinical reason, and support that tissue was obtained. The service has a 0-day global period, so same-day preoperative and postoperative care is included. When related endoscopies are performed together, CMS endoscopy-family pricing applies. Modifier 50 is inappropriate. Medicare does not pay an assistant at surgery for this service, and co-surgeon and team-surgery billing are not permitted.

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 Metropolitan Boston, MA compares for 45331

Across 109 of 109 payment localities, the office rate for 45331 runs from $281.06 in Arkansas to $449.20 in San Benito County, CA. Metropolitan Boston, MA pays $378.55. The RVUs are the same everywhere; the geographic indexes change the dollars.

45331 in Metropolitan Boston, MA vs other payment areas
  1. Metropolitan Boston, MA · this page$378.55
  2. Rest of Massachusetts · Massachusetts$337.54−$41.01
  3. Los Angeles, CA · California$374.40−$4.15
  4. Washington, DC area · District of Columbia$375.58−$2.97
  5. Miami, FL · Florida$341.67−$36.88
  6. Chicago, IL · Illinois$330.71−$47.84
  7. Manhattan, NY · New York$373.66−$4.89

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

Every other payment area

45331 in every other Medicare payment locality
Payment localityOfficeFacility
AlaskaAlaska$357.70$84.87
AlabamaAlabama$285.80$61.64
ArkansasArkansas$281.06$61.00
ArizonaArizona$313.60$65.35
Bakersfield, CACalifornia$348.86$68.08
Chico, CACalifornia$348.45$67.67
El Centro, CACalifornia$348.47$67.69
Fresno, CACalifornia$348.45$67.67

45331 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.

$281.06

$398.83

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

View every state and territory as a table
45331 office rate range by state
State / territoryOffice rate rangeLocalities
AK$357.701
AL$285.801
AR$281.061
AZ$313.601
CA$348.45–$449.2029
CO$340.411
CT$346.371
DC$375.581
DE$319.321
FL$312.96–$341.673
GA$293.51–$328.542
GU$359.551
HI$359.551
IA$296.261
ID$298.021
IL$301.15–$334.454
IN$300.051
KS$293.671
KY$291.371
LA$290.45–$307.032
MA$337.54–$378.552
MD$326.35–$375.583
ME$298.72–$318.732
MI$299.12–$316.352
MN$327.851
MO$284.05–$309.503
MS$282.671
MT$322.981
NC$302.461
ND$320.211
NE$298.421
NH$333.931
NJ$350.80–$370.642
NM$300.581
NV$322.491
NY$307.54–$382.525
OH$298.561
OK$291.851
OR$320.47–$353.602
PA$299.67–$336.092
PR$326.011
RI$332.471
SC$300.911
SD$319.881
TN$295.231
TX$297.34–$338.848
UT$305.641
VA$316.83–$375.582
VI$326.011
VT$317.861
WA$337.26–$387.832
WI$307.941
WV$288.161
WY$321.771

See 45331 in every payment locality

How the 45331 rate is calculated

Each of 45331’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 · 45331

RVUs × geographic indexes × conversion factor

Office or facility?

Work1.11

1.11 RVUs× 1.000 GPCI

Practice expense8.42

8.42 RVUs× 1.000 GPCI

Malpractice0.14

0.14 RVUs× 1.000 GPCI

Adjusted RVUs

9.6700

Conversion factor

$33.4009

Medicare rate

$322.99

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

The exact Metropolitan Boston, MA inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

5,499

Code
45331
Physician work
1.11
Practice expense
8.42
Malpractice
0.14

GPCI2026.csv

62

Locality
Metropolitan Boston, MA
Physician work
1.041
Practice expense
1.194
Malpractice
0.890
Office calculation for 45331 in Metropolitan Boston, MA
ComponentRVULocality factorAdjusted
Physician work1.11× 1.0411.1555
Practice expense8.42× 1.19410.0535
Malpractice0.14× 0.8900.1246
Total RVUs11.3336
Conversion factor× 33.4009

Office rate, Metropolitan Boston, MA$378.55

Office: (1.11 × 1.041 + 8.42 × 1.194 + 0.14 × 0.89) × $33.4009 = $378.55

Facility: (1.11 × 1.041 + 0.75 × 1.194 + 0.14 × 0.89) × $33.4009 = $72.67

Open 45331 in the RVU calculator

Payment rules and modifiers for 45331

The CMS indicators that decide how 45331 is paid alongside other services.

CMS payment indicators · 45331

Sigmoidoscopy, with biopsy

RuleCMS valueWhat it means
Global period000Same-day global: pre- and post-op care on the day of the procedure is included.
Multiple procedures3Endoscopy family rules apply.
Bilateral (modifier 50)0The 150% bilateral adjustment doesn’t apply.
Assistant at surgery (80/81/82/AS)1Not paid (statutory restriction).
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.

What modifiers do to the payment

Modifier 51 · payment effect

With and without the modifier

45331 without 51 · national office

$322.99

Sigmoidoscopy, with biopsy

45331-51 · Second procedure: 50%

$161.50

When this isn’t the highest-valued procedure in the session, Medicare pays 50% of its fee schedule amount (the highest is paid at 100%).

When to use modifier 51

Codes related to 45331

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

Codes related to 45331
CodeHow it relatesOffice range, Metropolitan Boston, MA
Same family
45330Flexible sigmoidoscopy, diagnosticFlexible sigmoidoscopy for diagnostic inspection without biopsy or another intervention.$251.42
45333Flexible sigmoidoscopy, hot biopsy forceps removalFlexible sigmoidoscopy with polyp removal rather than tissue sampling alone.$429.53
Used instead
45305Proctosigmoidoscopy, rigid scope with biopsyBiopsy during proctosigmoidoscopy, using a different endoscopic examination.$229.14
45342Sigmoidoscopy, ultrasound-guided tissue samplingBiopsy performed with endoscopic ultrasound guidance during sigmoidoscopy.No office rate

How 45331 has changed in Metropolitan Boston, MA

45331 · Office / nonfacility

$378.55

Effective 2026-10-01

The base rate is $60.21 higher than on 2025-10-01, moving from $318.34 to $378.55 (18.9%).

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

    $318.34changed to$378.55

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 1.14 changed to 1.11
    • Practice expense RVU 7.11 changed to 8.42
    • Malpractice RVU 0.16 changed to 0.14
    • Work GPCI 1.042 changed to 1.041
    • Practice expense GPCI 1.197 changed to 1.194
    • Malpractice GPCI 0.894 changed to 0.890

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $334.48changed to$318.34

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 7.29 changed to 7.11
    • Malpractice RVU 0.15 changed to 0.16

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $329.02changed to$334.48

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $343.37changed to$329.02

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 7.35 changed to 7.29
    • Malpractice RVU 0.14 changed to 0.15
    • Work GPCI 1.045 changed to 1.042
    • Practice expense GPCI 1.200 changed to 1.197
    • Malpractice GPCI 0.868 changed to 0.894

  5. January 1, 2023

    RVU23A

    $360.45changed to$343.37

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 7.58 changed to 7.35
    • Malpractice RVU 0.12 changed to 0.14
    • Work GPCI 1.049 changed to 1.045
    • Practice expense GPCI 1.203 changed to 1.200
    • Malpractice GPCI 0.842 changed to 0.868

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $360.66changed to$360.45

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 7.50 changed to 7.58
    • Malpractice RVU 0.14 changed to 0.12

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $329.26changed to$360.66

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 6.56 changed to 7.50
    • Malpractice RVU 0.13 changed to 0.14
    • Work GPCI 1.041 changed to 1.049
    • Practice expense GPCI 1.191 changed to 1.203
    • Malpractice GPCI 0.952 changed to 0.842

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $316.29changed to$329.26

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 6.31 changed to 6.56
    • Malpractice RVU 0.15 changed to 0.13
    • Work GPCI 1.033 changed to 1.041
    • Practice expense GPCI 1.179 changed to 1.191
    • Malpractice GPCI 1.061 changed to 0.952

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $305.76changed to$316.29

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 6.07 changed to 6.31

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $297.77changed to$305.76

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 5.98 changed to 6.07
    • Work GPCI 1.025 changed to 1.033
    • Practice expense GPCI 1.171 changed to 1.179
    • Malpractice GPCI 0.839 changed to 1.061

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $293.83changed to$297.77

    • Conversion factor 35.8043 changed to 35.8887
    • Work GPCI 1.017 changed to 1.025
    • Practice expense GPCI 1.163 changed to 1.171
    • Malpractice GPCI 0.617 changed to 0.839

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $184.54changed to$293.83

    • Conversion factor 35.9335 changed to 35.8043
    • Work RVU 1.15 changed to 1.14
    • Practice expense RVU 3.32 changed to 5.98
    • Malpractice RVU 0.17 changed to 0.15

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $183.62changed to$184.54

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $182.80changed to$183.62

    • Conversion factor 35.8228 changed to 35.7547
    • Practice expense RVU 3.30 changed to 3.32
    • Work GPCI 1.016 changed to 1.017
    • Practice expense GPCI 1.156 changed to 1.163
    • Malpractice GPCI 0.704 changed to 0.617

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    No ratechanged to$182.80

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: No rate

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$378.55$72.67RVU26D
2026-07-01$378.55$72.67RVU26C
2026-04-01$378.55$72.67RVU26B
2026-01-01$378.55$72.67RVU26A
2025-10-01$318.34$76.74RVU25D
2025-07-01$318.34$76.74RVU25C
2025-04-01$318.34$76.74RVU25B
2025-01-01$318.34$76.74RVU25A
2024-10-01$334.48$78.27RVU24D
2024-07-01$334.48$78.27RVU24C
2024-04-01$334.48$78.27RVU24B
2024-03-09$334.48$78.27RVU24AR
2024-01-01$329.02$76.99RVU24A
2023-10-01$343.37$78.65RVU23D
2023-07-01$343.37$78.65RVU23C
2023-04-01$343.37$78.65RVU23B
2023-01-01$343.37$78.65RVU23A
2022-10-01$360.45$79.43RVU22D
2022-07-01$360.45$79.43RVU22C
2022-04-01$360.45$79.43RVU22B
2022-01-01$360.45$79.43RVU22A
2021-10-01$360.66$79.84RVU21D
2021-07-01$360.66$79.84RVU21C
2021-04-01$360.66$79.84RVU21B
2021-01-01$360.66$79.84RVU21A
2020-10-01$329.26$81.25RVU20D
2020-07-01$329.26$81.25RVU20C
2020-04-01$329.26$81.25RVU20B
2020-01-01$329.26$81.25RVU20A
2019-10-01$316.29$81.74RVU19D
2019-07-01$316.29$81.74RVU19C
2019-04-01$316.29$81.74RVU19B
2019-01-01$316.29$81.74RVU19A
2018-10-01$305.76$82.50RVU18D
2018-07-01$305.76$82.50RVU18C
2018-04-01$305.76$82.50RVU18B
2018-01-01$305.76$82.50RVU18AR1
2017-10-01$297.77$80.91RVU17D
2017-07-01$297.77$80.91RVU17C
2017-04-01$297.77$80.91RVU17B
2017-01-01$297.77$80.91RVU17A
2016-10-01$293.83$78.55RVU16D
2016-07-01$293.83$78.55RVU16C
2016-04-01$293.83$78.55RVU16B
2016-01-01$293.83$78.55RVU16A
2015-10-01$184.54$80.90RVU15D
2015-07-01$184.54$80.90RVU15C
2015-04-01$183.62$80.50RVU15B
2015-01-01$183.62$80.50RVU15A
2014-10-01$182.80$80.93RVU14D
2014-07-01$182.80$80.93RVU14C
2014-04-01$182.80$80.93RVU14B
2014-01-01$182.80$80.93RVU14A
2013-10-01Rate data unavailableRate data unavailableRVU13D
2013-07-01Rate data unavailableRate data unavailableRVU13C
2013-04-01Rate data unavailableRate data unavailableRVU13B
2013-01-01Rate data unavailableRate data unavailableRVU13AR

Price 45331 for an earlier date of service

Where the Metropolitan Boston, MA rate applies

Metropolitan Boston, MA is a Medicare payment area, not a city. Our Census mapping connects it to 60 cities and communities in Massachusetts. Some span more than one payment area; confirm with the service ZIP.

  • Boston
  • Arlington
  • Ayer
  • Bellingham
  • Belmont
  • Braintree Town
  • Brookline
  • Burlington

Browse all communities in Massachusetts

45331 billing questions

How does this differ from diagnostic sigmoidoscopy?

Use 45331 when the flexible examination includes tissue sampling. Use 45330 when the examination is diagnostic without biopsy or another reportable intervention.

Can multiple biopsy samples be reported as multiple units?

No. The code covers one or multiple biopsies during the sigmoidoscopy; the number of specimens alone does not create additional units.

Can the biopsy and a polypectomy be reported together?

A biopsy that is simply part of removing the same lesion should not be represented separately as a diagnostic biopsy. Distinct sampling or treatment requires documentation of what was done and where.

Should modifier 50 be used for biopsies on both sides?

No. CMS identifies bilateral adjustment as inappropriate for this code, and modifier 50 should not be used.

Is same-day care included in the payment?

Yes. The 0-day global period includes same-day preoperative and postoperative care.

Can an assistant surgeon or co-surgeon be billed?

Medicare does not pay an assistant at surgery for this service. Co-surgeon and team-surgery billing are not permitted.

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 45331PPRRVU2026_Oct_nonQPP.csv, line 5,499 (RVU26D)
Geographic factors for Metropolitan Boston, MAGPCI2026.csv, line 62 (RVU26D)

Open CMS sourceHow we calculate rates

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