CPT code 45303: Proctosigmoidoscopy, dilation of a narrowing2026 Medicare rate & RVUs in Massachusetts
Report rigid proctosigmoidoscopy with dilation when the endoscopist treats a narrowing in the rectum or distal sigmoid under direct visualization.
Medicare pays $1,076.09–$1,215.00 for 45303 in the office in Massachusetts, from Rest of Massachusetts to Metropolitan Boston, MA. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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What 45303 covers
This service combines examination of the rectum and distal sigmoid with dilation of a narrowing seen during rigid proctosigmoidoscopy. A gastroenterologist, colorectal surgeon, or other qualified endoscopist may perform it when a stricture limits passage through the examined segment. The clinician uses a dilation method suited to the narrowing and the patient; the procedure is therapeutic, not simply an inspection of the area.
Report the service when the record supports both rigid proctosigmoidoscopic examination and dilation. Document the narrowing’s location, the treatment performed, and the findings. CMS assigns a 0-day global period, so same-day preoperative and postoperative care is included. When related endoscopies are performed together, endoscopy-family pricing applies. Modifier 50 is inappropriate for this service. Medicare does not pay for an assistant at surgery; 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.
Where 45303 pays more and less in Massachusetts
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Boston, MA | $1,215.00 | $86.38 |
| Rest of Massachusetts | $1,076.09 | $80.75 |
How the 45303 rate is calculated
Each of 45303’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 · 45303
RVUs × geographic indexes × conversion factor
Work1.37
1.37 RVUs× 1.000 GPCI
Practice expense29.10
29.10 RVUs× 1.000 GPCI
Malpractice0.23
0.23 RVUs× 1.000 GPCI
Adjusted RVUs
30.7000
Conversion factor
$33.4009
Medicare rate
$1,025.41
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 45303
The CMS indicators that decide how 45303 is paid alongside other services.
CMS payment indicators · 45303
Proctosigmoidoscopy, dilation of a narrowing
| 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
45303 without 51 · national office
$1,025.41
Proctosigmoidoscopy, dilation of a narrowing
45303-51 · Second procedure: 50%
$512.71
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%).
45303 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 45300ProctosigmoidoscopyRigid, diagnostic
- Use 45300 for diagnostic rigid proctosigmoidoscopy without dilation. Use 45303 when the endoscopist dilates a narrowing during the examination.
- 45305ProctosigmoidoscopyRigid scope with biopsy
- 45305 includes biopsy with rigid proctosigmoidoscopy. It describes tissue sampling, while 45303 describes dilation of a narrowing.
- 45340Sigmoidoscopy dilationTransendoscopic balloon
- 45340 describes dilation with flexible sigmoidoscopy. Choose between it and 45303 based on the scope type used for the procedure.
45303 billing questions
How does this differ from 45300?
45300 describes rigid proctosigmoidoscopy for diagnostic examination alone. Report 45303 when the examination includes dilation of a narrowing.
How does this differ from 45340?
45303 is for dilation performed with rigid proctosigmoidoscopy. 45340 describes dilation performed with flexible sigmoidoscopy.
What documentation supports this code?
Document the rigid examination, the narrowing’s location, and the dilation performed. The record should make clear that treatment occurred, not just diagnostic inspection.
Can modifier 50 be used?
No. CMS identifies bilateral adjustment as inappropriate for this code.
How are related endoscopies priced when performed together?
CMS applies endoscopy-family pricing when related endoscopies are performed together. The code has a 0-day global period, which includes same-day preoperative and postoperative care.
Can an assistant surgeon or co-surgeon be billed?
Medicare does not pay an assistant-at-surgery claim 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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