CPT code 31233: Sinus endoscopy, maxillary sinus2026 Medicare rate & RVUs in South Dakota

Reports diagnostic endoscopic inspection of the maxillary sinus through the nasal passage when the clinician evaluates disease within that sinus.

CMS RVU26DEffective Oct 1, 2026One payment locality3.8K Medicare services in 2024

In South Dakota, Medicare pays $265.90 for 31233 in the office and $110.58 when it’s performed in a hospital or facility.

$265.90Office (non-facility)
$110.58Hospital or facility
−2.4%vs the national office rate ($272.55)

Check a contract rate as a % of Medicare · 31233 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 31233 for the payment locality that covers the ZIP.

On this page 11 sections
  1. Rate in South Dakota
  2. What 31233 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 31233 covers

An otolaryngologist or rhinologist passes an endoscope through the nasal cavity and into the maxillary sinus through its natural opening to inspect the sinus. The examination may help evaluate suspected maxillary sinus disease, such as persistent symptoms or an abnormal finding that requires direct visualization. This is distinct from an examination confined to the nasal cavity and from operative enlargement of the sinus opening or removal of tissue.

Report the service when the maxillary sinus is entered and diagnostically examined; document the approach, side or sides examined, and relevant findings. The code has a 0-day global period, so same-day preoperative and postoperative care is included. When related endoscopies are performed together, endoscopy family pricing applies. For bilateral reporting, modifier 50 is paid at 150%. Assistant-at-surgery payment requires documentation of medical necessity; co-surgeons and team surgery 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 South Dakota compares for 31233

Across 109 of 109 payment localities, the office rate for 31233 runs from $240.71 in Arkansas to $360.32 in San Benito County, CA. South Dakota pays $265.90. The RVUs are the same everywhere; the geographic indexes change the dollars.

31233 in South Dakota vs other payment areas
  1. South Dakota · this page$265.90
  2. Los Angeles, CA · California$307.13+$41.23
  3. Washington, DC area · District of Columbia$311.59+$45.69
  4. Miami, FL · Florida$295.72+$29.82
  5. Chicago, IL · Illinois$286.98+$21.08
  6. Manhattan, NY · New York$313.98+$48.08
  7. Alaska · Alaska$316.06+$50.16

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

Every other payment area

31233 in every other Medicare payment locality
Payment localityOfficeFacility
AlabamaAlabama$244.28$108.38
ArkansasArkansas$240.71$107.29
ArizonaArizona$265.18$114.68
Bakersfield, CACalifornia$288.36$118.13
Chico, CACalifornia$287.48$117.26
El Centro, CACalifornia$287.53$117.31
Fresno, CACalifornia$287.48$117.26
Hanford, CACalifornia$287.48$117.26

31233 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.

$240.71

$323.90

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

View every state and territory as a table
31233 office rate range by state
State / territoryOffice rate rangeLocalities
AK$316.061
AL$244.281
AR$240.711
AZ$265.181
CA$287.48–$360.3229
CO$283.461
CT$290.821
DC$311.591
DE$269.601
FL$269.17–$295.723
GA$253.81–$277.842
GU$294.551
HI$294.551
IA$250.241
ID$251.961
IL$261.54–$286.984
IN$253.431
KS$249.211
KY$250.461
LA$250.12–$262.622
MA$281.80–$311.502
MD$274.74–$311.593
ME$253.45–$267.132
MI$257.19–$272.732
MN$271.051
MO$245.88–$263.383
MS$243.331
MT$272.531
NC$256.111
ND$266.601
NE$251.581
NH$279.151
NJ$293.98–$308.342
NM$258.681
NV$271.071
NY$260.01–$321.865
OH$255.981
OK$249.841
OR$268.81–$292.372
PA$256.31–$283.612
PR$274.511
RI$279.141
SC$256.501
SD$265.901
TN$250.501
TX$254.62–$282.658
UT$260.051
VA$266.35–$311.592
VI$274.511
VT$265.691
WA$281.22–$317.722
WI$257.581
WV$251.801
WY$269.951

See 31233 in every payment locality

How the 31233 rate is calculated

Each of 31233’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 · 31233

RVUs × geographic indexes × conversion factor

Office or facility?

Work2.13

2.13 RVUs× 1.000 GPCI

Practice expense5.73

5.73 RVUs× 1.000 GPCI

Malpractice0.30

0.30 RVUs× 1.000 GPCI

Adjusted RVUs

8.1600

Conversion factor

$33.4009

Medicare rate

$272.55

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

The exact South Dakota inputs and CMS source lines

PPRRVU2026_Oct_nonQPP.csv

3,525

Code
31233
Physician work
2.13
Practice expense
5.73
Malpractice
0.30

GPCI2026.csv

94

Locality
South Dakota
Physician work
1.000
Practice expense
1.000
Malpractice
0.336
Office calculation for 31233 in South Dakota
ComponentRVULocality factorAdjusted
Physician work2.13× 1.0002.1300
Practice expense5.73× 1.0005.7300
Malpractice0.30× 0.3360.1008
Total RVUs7.9608
Conversion factor× 33.4009

Office rate, South Dakota$265.90

Office: (2.13 × 1 + 5.73 × 1 + 0.3 × 0.336) × $33.4009 = $265.90

Facility: (2.13 × 1 + 1.08 × 1 + 0.3 × 0.336) × $33.4009 = $110.58

Open 31233 in the RVU calculator

Payment rules and modifiers for 31233

The CMS indicators that decide how 31233 is paid alongside other services.

CMS payment indicators · 31233

Sinus endoscopy, maxillary sinus

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)1Bilateral with modifier 50 pays 150% of the fee schedule amount.
Assistant at surgery (80/81/82/AS)0Not paid without supporting documentation.
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.

What modifiers do to the payment

Modifier 50 · payment effect

With and without the modifier

31233 without 50 · national office

$272.55

Sinus endoscopy, maxillary sinus

31233-50 · Bilateral: 150%

$408.83

Both sides on one line with modifier 50 are paid at 150% of the fee schedule amount (subject to multiple-procedure rules with other procedures).

When to use modifier 50

How 31233 has changed in South Dakota

31233 · Office / nonfacility

$265.90

Effective 2026-10-01

The base rate is $9.89 higher than on 2025-10-01, moving from $256.01 to $265.90 (3.9%).

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

    $256.01changed to$265.90

    • Conversion factor 32.3465 changed to 33.4009
    • Work RVU 2.18 changed to 2.13
    • Practice expense RVU 5.62 changed to 5.73
    • Malpractice GPCI 0.382 changed to 0.336

    Held through RVU26B, RVU26C, RVU26D.

  2. January 1, 2025

    RVU25A

    $268.04changed to$256.01

    • Conversion factor 33.2875 changed to 32.3465
    • Practice expense RVU 5.75 changed to 5.62
    • Malpractice RVU 0.32 changed to 0.30

    Held through RVU25B, RVU25C, RVU25D.

  3. March 9, 2024

    RVU24AR

    $263.66changed to$268.04

    • Conversion factor 32.7442 changed to 33.2875

    Held through RVU24B, RVU24C, RVU24D.

  4. January 1, 2024

    RVU24A

    $274.12changed to$263.66

    • Conversion factor 33.8872 changed to 32.7442
    • Practice expense RVU 5.80 changed to 5.75
    • Malpractice RVU 0.30 changed to 0.32
    • Malpractice GPCI 0.364 changed to 0.382
  5. January 1, 2023

    RVU23A

    $278.15changed to$274.12

    • Conversion factor 34.6062 changed to 33.8872
    • Practice expense RVU 5.75 changed to 5.80
    • Malpractice RVU 0.31 changed to 0.30
    • Malpractice GPCI 0.347 changed to 0.364

    Held through RVU23B, RVU23C, RVU23D.

  6. January 1, 2022

    RVU22A

    $271.96changed to$278.15

    • Conversion factor 34.8931 changed to 34.6062
    • Practice expense RVU 5.51 changed to 5.75
    • Malpractice RVU 0.30 changed to 0.31

    Held through RVU22B, RVU22C, RVU22D.

  7. January 1, 2021

    RVU21A

    $262.02changed to$271.96

    • Conversion factor 36.0896 changed to 34.8931
    • Practice expense RVU 4.97 changed to 5.51
    • Malpractice GPCI 0.368 changed to 0.347

    Held through RVU21B, RVU21C, RVU21D.

  8. January 1, 2020

    RVU20A

    $260.22changed to$262.02

    • Conversion factor 36.0391 changed to 36.0896
    • Practice expense RVU 4.92 changed to 4.97
    • Malpractice RVU 0.31 changed to 0.30
    • Malpractice GPCI 0.389 changed to 0.368

    Held through RVU20B, RVU20C, RVU20D.

  9. January 1, 2019

    RVU19A

    $256.92changed to$260.22

    • Conversion factor 35.9996 changed to 36.0391
    • Practice expense RVU 4.84 changed to 4.92
    • Malpractice RVU 0.30 changed to 0.31

    Held through RVU19B, RVU19C, RVU19D.

  10. January 1, 2018

    RVU18AR1

    $259.56changed to$256.92

    • Conversion factor 35.8887 changed to 35.9996
    • Practice expense RVU 4.93 changed to 4.84
    • Malpractice RVU 0.31 changed to 0.30
    • Malpractice GPCI 0.395 changed to 0.389

    Held through RVU18B, RVU18C, RVU18D.

  11. January 1, 2017

    RVU17A

    $262.59changed to$259.56

    • Conversion factor 35.8043 changed to 35.8887
    • Practice expense RVU 5.03 changed to 4.93
    • Malpractice GPCI 0.400 changed to 0.395

    Held through RVU17B, RVU17C, RVU17D.

  12. January 1, 2016

    RVU16A

    $262.24changed to$262.59

    • Conversion factor 35.9335 changed to 35.8043
    • Practice expense RVU 4.99 changed to 5.03
    • Malpractice RVU 0.32 changed to 0.31

    Held through RVU16B, RVU16C, RVU16D.

  13. July 1, 2015

    RVU15C

    $260.94changed to$262.24

    • Conversion factor 35.7547 changed to 35.9335

    Held through RVU15D.

  14. January 1, 2015

    RVU15A

    $264.25changed to$260.94

    • Conversion factor 35.8228 changed to 35.7547
    • Practice expense RVU 5.08 changed to 4.99
    • Malpractice RVU 0.28 changed to 0.32
    • Malpractice GPCI 0.416 changed to 0.400

    Held through RVU15B.

  15. January 1, 2014

    RVU14A

    $270.32changed to$264.25

    • Conversion factor 34.0230 changed to 35.8228
    • Practice expense RVU 5.64 changed to 5.08
    • Malpractice RVU 0.29 changed to 0.28
    • Malpractice GPCI 0.432 changed to 0.416

    Held through RVU14B, RVU14C, RVU14D.

  16. January 1, 2013

    RVU13AR

    Earliest loaded release: $270.32

    Held through RVU13B, RVU13C, RVU13D.

Rates in every CMS release
Effective fromOfficeFacilityCMS release
2026-10-01$265.90$110.58RVU26D
2026-07-01$265.90$110.58RVU26C
2026-04-01$265.90$110.58RVU26B
2026-01-01$265.90$110.58RVU26A
2025-10-01$256.01$125.33RVU25D
2025-07-01$256.01$125.33RVU25C
2025-04-01$256.01$125.33RVU25B
2025-01-01$256.01$125.33RVU25A
2024-10-01$268.04$128.56RVU24D
2024-07-01$268.04$128.56RVU24C
2024-04-01$268.04$128.56RVU24B
2024-03-09$268.04$128.56RVU24AR
2024-01-01$263.66$126.47RVU24A
2023-10-01$274.12$129.76RVU23D
2023-07-01$274.12$129.76RVU23C
2023-04-01$274.12$129.76RVU23B
2023-01-01$274.12$129.76RVU23A
2022-10-01$278.15$130.04RVU22D
2022-07-01$278.15$130.04RVU22C
2022-04-01$278.15$130.04RVU22B
2022-01-01$278.15$130.04RVU22A
2021-10-01$271.96$129.25RVU21D
2021-07-01$271.96$129.25RVU21C
2021-04-01$271.96$129.25RVU21B
2021-01-01$271.96$129.25RVU21A
2020-10-01$262.02$131.74RVU20D
2020-07-01$262.02$131.74RVU20C
2020-04-01$262.02$131.74RVU20B
2020-01-01$262.02$131.74RVU20A
2019-10-01$260.22$132.65RVU19D
2019-07-01$260.22$132.65RVU19C
2019-04-01$260.22$132.65RVU19B
2019-01-01$260.22$132.65RVU19A
2018-10-01$256.92$132.00RVU18D
2018-07-01$256.92$132.00RVU18C
2018-04-01$256.92$132.00RVU18B
2018-01-01$256.92$132.00RVU18AR1
2017-10-01$259.56$133.59RVU17D
2017-07-01$259.56$133.59RVU17C
2017-04-01$259.56$133.59RVU17B
2017-01-01$259.56$133.59RVU17A
2016-10-01$262.59$134.41RVU16D
2016-07-01$262.59$134.41RVU16C
2016-04-01$262.59$134.41RVU16B
2016-01-01$262.59$134.41RVU16A
2015-10-01$262.24$134.68RVU15D
2015-07-01$262.24$134.68RVU15C
2015-04-01$260.94$134.01RVU15B
2015-01-01$260.94$134.01RVU15A
2014-10-01$264.25$135.64RVU14D
2014-07-01$264.25$135.64RVU14C
2014-04-01$264.25$135.64RVU14B
2014-01-01$264.25$135.64RVU14A
2013-10-01$270.32$133.21RVU13D
2013-07-01$270.32$133.21RVU13C
2013-04-01$270.32$133.21RVU13B
2013-01-01$270.32$133.21RVU13AR

Price 31233 for an earlier date of service

Where the South Dakota rate applies

South Dakota is a Medicare payment area, not a city. Our Census mapping connects it to 485 cities and communities in South Dakota. Some span more than one payment area; confirm with the service ZIP.

  • Aberdeen
  • Agar
  • Agency Village
  • Akaska
  • Albee
  • Alcester
  • Alexandria
  • Allen

Browse all communities in South Dakota

31233 billing questions

How does this differ from 31231?

31231 describes diagnostic nasal endoscopy limited to the nasal cavity. Use 31233 when the scope is advanced into and used to inspect the maxillary sinus.

How does this differ from 31235?

31235 is the diagnostic endoscopic examination of the sphenoid sinus. Code 31233 is for diagnostic examination of the maxillary sinus.

Can 31233 be reported with another endoscopy code?

Related endoscopies may be performed together, but CMS endoscopy family pricing applies. Document the distinct anatomic sites and services performed.

How is bilateral work reported?

For bilateral performance, report modifier 50; CMS pays 31233 at 150%. Document examination of both maxillary sinuses.

Can 31233 be reported for a maxillary antrostomy?

No. A diagnostic examination through the natural sinus opening is different from operative creation or enlargement of an opening, such as the service represented by 31256.

What documentation supports 31233?

Record that the endoscope entered the maxillary sinus, the side examined, and the diagnostic findings. A note describing nasal-cavity inspection alone supports a different service.

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 31233PPRRVU2026_Oct_nonQPP.csv, line 3,525 (RVU26D)
Geographic factors for South DakotaGPCI2026.csv, line 94 (RVU26D)

Open CMS sourceHow we calculate rates

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