CPT code 91117: Colon motility, six-hour study2026 Medicare rate & RVUs in Missouri
Reports prolonged colonic pressure monitoring used to evaluate suspected colon motility disorders, including severe or treatment-resistant constipation.
CMS doesn’t publish an office rate for 91117 in Missouri.
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 91117 covers
This service is an extended manometric assessment of colonic motor activity, with pressure data interpreted and reported. Gastroenterologists and other clinicians specializing in gastrointestinal motility typically perform or interpret it in a setting equipped for prolonged physiologic monitoring. It can help evaluate suspected colonic dysmotility in patients with persistent constipation when a focused assessment of colon function is needed.
Select this code for the prolonged colon motility study, rather than a study that measures transit with a wireless capsule or evaluates anorectal function. The record should identify the study performed, its duration, and the interpreted findings supporting the assessment. The 0-day global period includes same-day preoperative and postoperative care. Modifier 50 is not appropriate for this single-colon study. Medicare assistant-at-surgery payment requires documented 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.
Where 91117 pays more and less in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | Unavailable | $119.57 |
| Metropolitan St. Louis, MO | Unavailable | $120.19 |
| Rest of Missouri | Unavailable | $116.78 |
How the 91117 rate is calculated
Each of 91117’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 · 91117
RVUs × geographic indexes × conversion factor
Work2.39
2.39 RVUs× 1.000 GPCI
Practice expense1.08
1.08 RVUs× 1.000 GPCI
Malpractice0.18
0.18 RVUs× 1.000 GPCI
Adjusted RVUs
3.6500
Conversion factor
$33.4009
Medicare rate
$121.91
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 91117
The CMS indicators that decide how 91117 is paid alongside other services.
CMS payment indicators · 91117
Colon motility, six-hour study
| 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 | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
91117 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 91112Motility capsuleTransit and pressure measurement
- Choose 91117 for prolonged manometric assessment of colonic motor activity; 91112 uses a wireless capsule to measure gastrointestinal transit and pressure.
- 91124Rectal physiologySensation, tone, compliance
- 91124 evaluates anorectal sensation, tone, and compliance. It is not the prolonged colonic motility study reported with 91117.
- 91125Anorectal testingManometry with sensory testing
- 91125 is anorectal manometry with rectal sensation and balloon expulsion testing; 91117 assesses colonic motility over an extended study.
91117 billing questions
How does this differ from a wireless capsule study?
91117 reports prolonged manometric assessment of colonic motor activity. 91112 measures gastrointestinal transit and pressure using a wireless capsule.
Can the interpretation be billed separately?
The reported service includes interpretation and a report. The documentation should support the findings reported as part of the study.
Should modifier 50 be used?
No. Modifier 50 is not appropriate for this single-colon study.
What documentation supports reporting 91117?
Document the prolonged colonic motility study, its duration, and the interpreted pressure findings. A brief or different type of gastrointestinal function test does not establish this service.
How does this differ from anorectal testing?
91117 assesses colonic motility. Codes 91124 and 91125 concern anorectal function, including rectal sensation or manometry-related testing.
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
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