CPT code 91117: Colon motility, six-hour study2026 Medicare rate & RVUs in Montana
Reports prolonged colonic pressure monitoring used to evaluate suspected colon motility disorders, including severe or treatment-resistant constipation.
In Montana, Medicare pays $121.90 for 91117 in a facility. There’s no office rate.
Check a contract rate as a % of Medicare · 91117 nationwide
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 11 sections
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.
How Montana compares for 91117
Across 109 of 109 payment localities, the facility rate for 91117 runs from $113.91 in Arkansas to $161.47 in Alaska. Montana pays $121.90. The RVUs are the same everywhere; the geographic indexes change the dollars.
- Montana · this page$121.90
- Los Angeles, CA · California$129.77+$7.87
- Washington, DC area · District of Columbia$133.32+$11.42
- Miami, FL · Florida$132.58+$10.68
- Chicago, IL · Illinois$130.44+$8.54
- Manhattan, NY · New York$136.39+$14.49
- Alaska · Alaska$161.47+$39.57
Other areas in Montana first, then benchmark localities. Bars start at $0.
Every other payment area
| Payment locality | Office | Facility |
|---|---|---|
| AlabamaAlabama | — | $114.79 |
| ArkansasArkansas | — | $113.91 |
| ArizonaArizona | — | $119.93 |
| Bakersfield, CACalifornia | — | $124.54 |
| Chico, CACalifornia | — | $123.94 |
| El Centro, CACalifornia | — | $123.97 |
| Fresno, CACalifornia | — | $123.94 |
| Hanford, CACalifornia | — | $123.94 |
| Madera, CACalifornia | — | $123.94 |
| Merced, CACalifornia | — | $123.94 |
| Modesto, CACalifornia | — | $123.94 |
| Napa, CACalifornia | — | $135.46 |
| Oxnard, CACalifornia | — | $128.45 |
| Redding, CACalifornia | — | $123.94 |
| Rest of CaliforniaCalifornia | — | $123.94 |
| Riverside, CACalifornia | — | $125.93 |
| Sacramento, CACalifornia | — | $127.88 |
| Salinas, CACalifornia | — | $127.33 |
| San Diego, CACalifornia | — | $128.62 |
| Marin County, CACalifornia | — | $141.03 |
| San Francisco, CACalifornia | — | $140.83 |
| San Benito County, CACalifornia | — | $143.85 |
| Santa Clara County, CACalifornia | — | $143.01 |
| San Luis Obispo, CACalifornia | — | $125.49 |
| Santa Cruz, CACalifornia | — | $128.56 |
| Santa Maria, CACalifornia | — | $127.35 |
| Santa Rosa, CACalifornia | — | $129.74 |
| Stockton, CACalifornia | — | $123.94 |
| Vallejo, CACalifornia | — | $135.16 |
| Visalia, CACalifornia | — | $123.94 |
| Yuba City, CACalifornia | — | $123.94 |
| ColoradoColorado | — | $123.86 |
| ConnecticutConnecticut | — | $127.55 |
| DelawareDelaware | — | $121.27 |
| Fort Lauderdale, FLFlorida | — | $127.24 |
| Rest of FloridaFlorida | — | $123.35 |
| Atlanta, GAGeorgia | — | $123.94 |
| Rest of GeorgiaGeorgia | — | $119.17 |
| Hawaii, Guam, HIHawaii | — | $124.32 |
| IowaIowa | — | $115.22 |
| IdahoIdaho | — | $115.86 |
| East St. Louis, ILIllinois | — | $125.12 |
| Rest of IllinoisIllinois | — | $122.16 |
| Suburban Chicago, ILIllinois | — | $128.09 |
| IndianaIndiana | — | $116.19 |
| KansasKansas | — | $115.47 |
| KentuckyKentucky | — | $117.40 |
| New Orleans, LALouisiana | — | $120.60 |
| Rest of LouisianaLouisiana | — | $117.51 |
| Metropolitan Boston, MAMassachusetts | — | $131.52 |
| Rest of MassachusettsMassachusetts | — | $123.88 |
| Baltimore area, MDMaryland | — | $127.25 |
| Rest of MarylandMaryland | — | $122.65 |
| Rest of MaineMaine | — | $116.75 |
| Southern Maine, MEMaine | — | $119.37 |
| Detroit, MIMichigan | — | $124.78 |
| Rest of MichiganMichigan | — | $119.55 |
| MinnesotaMinnesota | — | $118.73 |
| Metropolitan Kansas City, MOMissouri | — | $119.57 |
| Metropolitan St. Louis, MOMissouri | — | $120.19 |
| Rest of MissouriMissouri | — | $116.78 |
| MississippiMississippi | — | $115.33 |
| North CarolinaNorth Carolina | — | $117.33 |
| North DakotaNorth Dakota | — | $118.34 |
| NebraskaNebraska | — | $115.40 |
| New HampshireNew Hampshire | — | $122.64 |
| Northern New JerseyNew Jersey | — | $133.12 |
| Rest of New JerseyNew Jersey | — | $129.01 |
| New MexicoNew Mexico | — | $120.13 |
| NevadaNevada | — | $120.95 |
| NYC suburbs and Long Island, NYNew York | — | $138.99 |
| Poughkeepsie and northern NYC suburbs, NYNew York | — | $130.20 |
| Queens, NYNew York | — | $136.24 |
| Rest of New YorkNew York | — | $118.32 |
| OhioOhio | — | $118.82 |
| OklahomaOklahoma | — | $116.71 |
| Portland, OROregon | — | $125.66 |
| Rest of OregonOregon | — | $119.98 |
| Metropolitan Philadelphia, PAPennsylvania | — | $125.99 |
| Rest of PennsylvaniaPennsylvania | — | $118.62 |
| Puerto RicoPuerto Rico | — | $122.22 |
| Rhode IslandRhode Island | — | $123.97 |
| South CarolinaSouth Carolina | — | $118.27 |
| South DakotaSouth Dakota | — | $117.92 |
| TennesseeTennessee | — | $115.85 |
| Austin, TXTexas | — | $123.48 |
| Beaumont, TXTexas | — | $118.24 |
| Brazoria, TXTexas | — | $120.90 |
| Dallas, TXTexas | — | $121.63 |
| Fort Worth, TXTexas | — | $121.35 |
| Galveston, TXTexas | — | $121.27 |
| Houston, TXTexas | — | $124.56 |
| Rest of TexasTexas | — | $119.49 |
| UtahUtah | — | $119.14 |
| VirginiaVirginia | — | $119.53 |
| Virgin Islands, VIUnited States Virgin Islands | — | $122.22 |
| VermontVermont | — | $118.58 |
| Rest of WashingtonWashington | — | $123.43 |
| King County, WAWashington | — | $132.99 |
| WisconsinWisconsin | — | $116.24 |
| West VirginiaWest Virginia | — | $119.78 |
| WyomingWyoming | — | $120.35 |
91117 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.
View every state and territory as a table
| State / territory | Office rate range | Localities |
|---|---|---|
| AK | No published base rate | 1 |
| AL | No published base rate | 1 |
| AR | No published base rate | 1 |
| AZ | No published base rate | 1 |
| CA | No published base rate | 29 |
| CO | No published base rate | 1 |
| CT | No published base rate | 1 |
| DC | No published base rate | 1 |
| DE | No published base rate | 1 |
| FL | No published base rate | 3 |
| GA | No published base rate | 2 |
| GU | No published base rate | 1 |
| HI | No published base rate | 1 |
| IA | No published base rate | 1 |
| ID | No published base rate | 1 |
| IL | No published base rate | 4 |
| IN | No published base rate | 1 |
| KS | No published base rate | 1 |
| KY | No published base rate | 1 |
| LA | No published base rate | 2 |
| MA | No published base rate | 2 |
| MD | No published base rate | 3 |
| ME | No published base rate | 2 |
| MI | No published base rate | 2 |
| MN | No published base rate | 1 |
| MO | No published base rate | 3 |
| MS | No published base rate | 1 |
| MT | No published base rate | 1 |
| NC | No published base rate | 1 |
| ND | No published base rate | 1 |
| NE | No published base rate | 1 |
| NH | No published base rate | 1 |
| NJ | No published base rate | 2 |
| NM | No published base rate | 1 |
| NV | No published base rate | 1 |
| NY | No published base rate | 5 |
| OH | No published base rate | 1 |
| OK | No published base rate | 1 |
| OR | No published base rate | 2 |
| PA | No published base rate | 2 |
| PR | No published base rate | 1 |
| RI | No published base rate | 1 |
| SC | No published base rate | 1 |
| SD | No published base rate | 1 |
| TN | No published base rate | 1 |
| TX | No published base rate | 8 |
| UT | No published base rate | 1 |
| VA | No published base rate | 2 |
| VI | No published base rate | 1 |
| VT | No published base rate | 1 |
| WA | No published base rate | 2 |
| WI | No published base rate | 1 |
| WV | No published base rate | 1 |
| WY | No published base rate | 1 |
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.
The exact Montana inputs and CMS source lines
PPRRVU2026_Oct_nonQPP.csv
11,633
- Code
- 91117
- Physician work
- 2.39
- Practice expense
- 1.08
- Malpractice
- 0.18
GPCI2026.csv
71
- Locality
- Montana
- Physician work
- 1.000
- Practice expense
- 1.000
- Malpractice
- 0.998
| Component | RVU | Locality factor | Adjusted |
|---|---|---|---|
| Physician work | 2.39 | × 1.000 | 2.3900 |
| Practice expense | 1.08 | × 1.000 | 1.0800 |
| Malpractice | 0.18 | × 0.998 | 0.1796 |
| Total RVUs | 3.6496 | ||
| Conversion factor | × 33.4009 | ||
Facility rate, Montana$121.90
Facility: (2.39 × 1 + 1.08 × 1 + 0.18 × 0.998) × $33.4009 = $121.90
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. |
How 91117 has changed in Montana
91117 · Office / nonfacility
Rate unavailable
Effective 2026-10-01
A rate is unavailable in one of these releases, so a change cannot be calculated.
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
| Effective from | Office | Facility | CMS release |
|---|---|---|---|
| 2026-10-01 | Not available in this setting | $121.90 | RVU26D |
| 2026-07-01 | Not available in this setting | $121.90 | RVU26C |
| 2026-04-01 | Not available in this setting | $121.90 | RVU26B |
| 2026-01-01 | Not available in this setting | $121.90 | RVU26A |
| 2025-10-01 | Not available in this setting | $130.24 | RVU25D |
| 2025-07-01 | Not available in this setting | $130.24 | RVU25C |
| 2025-04-01 | Not available in this setting | $130.24 | RVU25B |
| 2025-01-01 | Not available in this setting | $130.24 | RVU25A |
| 2024-10-01 | Not available in this setting | $133.69 | RVU24D |
| 2024-07-01 | Not available in this setting | $133.69 | RVU24C |
| 2024-04-01 | Not available in this setting | $133.69 | RVU24B |
| 2024-03-09 | Not available in this setting | $133.69 | RVU24AR |
| 2024-01-01 | Not available in this setting | $131.51 | RVU24A |
| 2023-10-01 | Not available in this setting | $135.41 | RVU23D |
| 2023-07-01 | Not available in this setting | $135.41 | RVU23C |
| 2023-04-01 | Not available in this setting | $135.41 | RVU23B |
| 2023-01-01 | Not available in this setting | $135.41 | RVU23A |
| 2022-10-01 | Not available in this setting | $137.94 | RVU22D |
| 2022-07-01 | Not available in this setting | $137.94 | RVU22C |
| 2022-04-01 | Not available in this setting | $137.94 | RVU22B |
| 2022-01-01 | Not available in this setting | $137.94 | RVU22A |
| 2021-10-01 | Not available in this setting | $138.06 | RVU21D |
| 2021-07-01 | Not available in this setting | $138.06 | RVU21C |
| 2021-04-01 | Not available in this setting | $138.06 | RVU21B |
| 2021-01-01 | Not available in this setting | $138.06 | RVU21A |
| 2020-10-01 | Not available in this setting | $143.12 | RVU20D |
| 2020-07-01 | Not available in this setting | $143.12 | RVU20C |
| 2020-04-01 | Not available in this setting | $143.12 | RVU20B |
| 2020-01-01 | Not available in this setting | $143.12 | RVU20A |
| 2019-10-01 | Not available in this setting | $146.58 | RVU19D |
| 2019-07-01 | Not available in this setting | $146.58 | RVU19C |
| 2019-04-01 | Not available in this setting | $146.58 | RVU19B |
| 2019-01-01 | Not available in this setting | $146.58 | RVU19A |
| 2018-10-01 | Not available in this setting | $147.14 | RVU18D |
| 2018-07-01 | Not available in this setting | $147.14 | RVU18C |
| 2018-04-01 | Not available in this setting | $147.14 | RVU18B |
| 2018-01-01 | Not available in this setting | $147.14 | RVU18AR1 |
| 2017-10-01 | Not available in this setting | $145.81 | RVU17D |
| 2017-07-01 | Not available in this setting | $145.81 | RVU17C |
| 2017-04-01 | Not available in this setting | $145.81 | RVU17B |
| 2017-01-01 | Not available in this setting | $145.81 | RVU17A |
| 2016-10-01 | Not available in this setting | $142.01 | RVU16D |
| 2016-07-01 | Not available in this setting | $142.01 | RVU16C |
| 2016-04-01 | Not available in this setting | $142.01 | RVU16B |
| 2016-01-01 | Not available in this setting | $142.01 | RVU16A |
| 2015-10-01 | Not available in this setting | $145.83 | RVU15D |
| 2015-07-01 | Not available in this setting | $145.83 | RVU15C |
| 2015-04-01 | Not available in this setting | $145.11 | RVU15B |
| 2015-01-01 | Not available in this setting | $145.11 | RVU15A |
| 2014-10-01 | Not available in this setting | $153.66 | RVU14D |
| 2014-07-01 | Not available in this setting | $153.66 | RVU14C |
| 2014-04-01 | Not available in this setting | $153.66 | RVU14B |
| 2014-01-01 | Not available in this setting | $153.66 | RVU14A |
| 2013-10-01 | Not available in this setting | $161.92 | RVU13D |
| 2013-07-01 | Not available in this setting | $161.92 | RVU13C |
| 2013-04-01 | Not available in this setting | $161.92 | RVU13B |
| 2013-01-01 | Not available in this setting | $161.92 | RVU13AR |
Where the Montana rate applies
Montana is a Medicare payment area, not a city. Our Census mapping connects it to 497 cities and communities in Montana. Some span more than one payment area; confirm with the service ZIP.
- Absarokee
- Acton
- Alberton
- Alder
- Alzada
- Amsterdam
- Anaconda-Deer Lodge County
- Antelope
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
Show the CMS file lines behind this rate
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