Billing code 45331: SigmoidoscopyMedicare rate & RVUs
Reports flexible sigmoidoscopy with one or more tissue biopsies when a clinician samples the rectum or distal colon for diagnosis.
Medicare pays $322.99 for 45331 nationally in the office and $66.80 in a hospital or facility. Local office rates run $281.06–$449.20.
Medicare rate · 45331
Sigmoidoscopy
Swap in your local Medicare rate.
- Work RVUs
- 1.11
- Total RVUs
- 9.67
- Global days
- 000
National rate · 2026
$322.99
Office setting, before claim adjustments.
See every locality for 45331 → · Billed by an NP, PA or therapist? →
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 10 sections
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.
Where 45331 pays more and less
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
109 payment localities
$281.06 to $449.20
109 of 109 payment localities
45331 rates by state
Office rate range in each state. Select a state to see its payment localities.
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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
| State / territory | Office rate range | Localities |
|---|---|---|
| AK | $357.70 | 1 |
| AL | $285.80 | 1 |
| AR | $281.06 | 1 |
| AZ | $313.60 | 1 |
| CA | $348.45–$449.20 | 29 |
| CO | $340.41 | 1 |
| CT | $346.37 | 1 |
| DC | $375.58 | 1 |
| DE | $319.32 | 1 |
| FL | $312.96–$341.67 | 3 |
| GA | $293.51–$328.54 | 2 |
| GU | $359.55 | 1 |
| HI | $359.55 | 1 |
| IA | $296.26 | 1 |
| ID | $298.02 | 1 |
| IL | $301.15–$334.45 | 4 |
| IN | $300.05 | 1 |
| KS | $293.67 | 1 |
| KY | $291.37 | 1 |
| LA | $290.45–$307.03 | 2 |
| MA | $337.54–$378.55 | 2 |
| MD | $326.35–$375.58 | 3 |
| ME | $298.72–$318.73 | 2 |
| MI | $299.12–$316.35 | 2 |
| MN | $327.85 | 1 |
| MO | $284.05–$309.50 | 3 |
| MS | $282.67 | 1 |
| MT | $322.98 | 1 |
| NC | $302.46 | 1 |
| ND | $320.21 | 1 |
| NE | $298.42 | 1 |
| NH | $333.93 | 1 |
| NJ | $350.80–$370.64 | 2 |
| NM | $300.58 | 1 |
| NV | $322.49 | 1 |
| NY | $307.54–$382.52 | 5 |
| OH | $298.56 | 1 |
| OK | $291.85 | 1 |
| OR | $320.47–$353.60 | 2 |
| PA | $299.67–$336.09 | 2 |
| PR | $326.01 | 1 |
| RI | $332.47 | 1 |
| SC | $300.91 | 1 |
| SD | $319.88 | 1 |
| TN | $295.23 | 1 |
| TX | $297.34–$338.84 | 8 |
| UT | $305.64 | 1 |
| VA | $316.83–$375.58 | 2 |
| VI | $326.01 | 1 |
| VT | $317.86 | 1 |
| WA | $337.26–$387.83 | 2 |
| WI | $307.94 | 1 |
| WV | $288.16 | 1 |
| WY | $321.77 | 1 |
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
Swap in your local Medicare rate.
Work 1.11Practice expense 8.42Malpractice 0.14
All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.
Payment rules and modifiers for 45331
The CMS indicators that decide how 45331 is paid alongside other services.
CMS payment indicators · 45331
Sigmoidoscopy
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 000 | Same-day global: pre- and post-op care on the day of the procedure is included. |
| Multiple procedures | 3 | Endoscopy family rules apply. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 1 | Not paid (statutory restriction). |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician 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
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%).
45331 compared with similar codes
Compare codes
45331 vs 45330 vs 45333 vs 45305: national Medicare rates
Swap in your local Medicare rate.
How to choose
- 45330Flexible sigmoidoscopy
- 45330 describes diagnostic flexible sigmoidoscopy without biopsy. Select 45331 when tissue is sampled during the examination.
- 45333Flexible sigmoidoscopy
- 45333 is for polyp removal during flexible sigmoidoscopy; 45331 is for biopsy sampling. Distinguish tissue sampling from removal of a lesion.
- 45305Proctosigmoidoscopy
- 45305 describes biopsy during proctosigmoidoscopy. Use 45331 for biopsy performed with flexible sigmoidoscopy.
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
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