$217.84–$278.92
Choose 91035 for wireless pH monitoring using an electrode attached to the esophageal lining. Choose 91034 for catheter-based pH monitoring.
On this page
CMS RVU26D · Effective 2026-10-01
91035 Reflux testing Medicare reimbursement rates in California
Reports ambulatory esophageal acid monitoring with a mucosa-attached wireless electrode to evaluate suspected gastroesophageal reflux and measure acid exposure. Compare 91035 office and facility rates across CMS payment localities in California.
Amounts below use the non-QP conversion factor for participating physicians. These are base physician payments before claim-level adjustments, not patient costs or total hospital charges.
What does Medicare pay for 91035 in California?
California has 29 payment localities in this comparison. Use the service location to choose the applicable amount. These are the supported base rates for the 29 payment areas shown below, using the same CMS release.
Office / nonfacility
$543.68–$702.66
29 of 29 localities have a supported rate.
Lowest: Chico
Highest: San Jose-Sunnyvale-Santa Clara (San Benito Cnty)
A spread of $158.98 per service.
Facility setting
No supported rate
These are locality ranges, not averages or address-specific quotes. A facility-setting amount covers the physician service; it does not include a hospital’s separate bill. Choose a locality below to inspect its calculation, compare other payment areas, or price a percentage of Medicare.
Where 91035 pays more and less in California
29 payment localities
$543.68 to $702.66
Gastroenterology testing
About 91035: Wireless esophageal pH monitoring
Reports ambulatory esophageal acid monitoring with a mucosa-attached wireless electrode to evaluate suspected gastroesophageal reflux and measure acid exposure.
This service uses a wireless pH electrode attached to the esophageal lining to collect acid readings during ambulatory monitoring. A gastroenterologist or other qualified clinician commonly places the electrode during an upper endoscopy; the patient then leaves with the recorder and follows instructions for documenting symptoms and activities. The completed study is analyzed to assess esophageal acid exposure and its relationship to reported symptoms, such as persistent heartburn or regurgitation.
Report 91035 for the wireless, mucosa-attached monitoring method, including electrode placement, recording, analysis, and interpretation. Documentation should identify the clinical reason for testing and support the recorded study and interpretation. The global service includes the professional interpretation and technical recording; modifier 26 identifies the professional component, while TC identifies the technical component. The 0-day global period includes same-day preoperative and postoperative care. Modifier 50 is inappropriate for this service. Assistant-at-surgery payment requires documented medical necessity; co-surgeon and team-surgery billing are not permitted.
CMS billing rules for 91035
- Global period
- Minor procedure with a 0-day global period: same-day preoperative and postoperative care is included.
- Professional and technical components
- Diagnostic test with a professional component (modifier 26, interpretation) and a technical component (modifier TC, equipment and staff); billing without a modifier is the global service.
- Bilateral procedures
- Bilateral adjustment does not apply; the descriptor or anatomy makes modifier 50 inappropriate.
- Assistant at surgery
- Assistant at surgery is paid only with documentation of medical necessity.
- Co-surgeons
- Co-surgeons not permitted.
- Team surgery
- Team surgery not permitted.
Where the value comes from
- Work RVU1.55 · 10%
- Practice expense (office) RVU13.34 · 89%
- Malpractice RVU0.15 · 1%
11.9K
Medicare services in 2024 · #1381 by national volume
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.
91035 compared with similar codes
Office rates for California, from the same CMS release.
$201.55–$257.55
91037 reports esophageal impedance testing, rather than the mucosa-attached wireless pH study reported with 91035.
$484.31–$628.37
91038 reports esophageal impedance testing for more than one hour. 91035 is the wireless mucosa-attached pH monitoring service.
Compare 91035 by payment locality
Find the payment area for your service address, then open its rate page for calculation inputs, release history and the percentage-of-Medicare tool. A city may cross payment-area boundaries; the ZIP lookup above helps resolve the location.
29 of 29 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Bakersfield | Office $544.15 | Facility Unavailable |
| Chico | Office $543.68 | Facility Unavailable |
| El Centro | Office $543.70 | Facility Unavailable |
| Fresno | Office $543.68 | Facility Unavailable |
| Hanford-Corcoran | Office $543.68 | Facility Unavailable |
| Los Angeles-Long Beach-Anaheim (Los Angeles/Orange Cnty) | Office $584.33 | Facility Unavailable |
| Madera | Office $543.68 | Facility Unavailable |
| Merced | Office $543.68 | Facility Unavailable |
| Modesto | Office $543.68 | Facility Unavailable |
| Napa | Office $644.84 | Facility Unavailable |
| Oxnard-Thousand Oaks-Ventura | Office $583.00 | Facility Unavailable |
| Redding | Office $543.68 | Facility Unavailable |
| Rest Of California | Office $543.68 | Facility Unavailable |
| Riverside-San Bernardino-Ontario | Office $545.32 | Facility Unavailable |
| Sacramento-Roseville-Folsom | Office $574.52 | Facility Unavailable |
| Salinas | Office $572.48 | Facility Unavailable |
| San Diego-Chula Vista-Carlsbad | Office $588.94 | Facility Unavailable |
| San Francisco-Oakland-Berkeley (Marin Cnty) | Office $687.24 | Facility Unavailable |
| San Francisco-Oakland-Berkeley (San Francisco/San Mateo/Alameda/Contra Costa Cnty) | Office $687.07 | Facility Unavailable |
| San Jose-Sunnyvale-Santa Clara (San Benito Cnty) | Office $702.66 | Facility Unavailable |
| San Jose-Sunnyvale-Santa Clara (Santa Clara Cnty) | Office $701.96 | Facility Unavailable |
| San Luis Obispo-Paso Robles | Office $562.84 | Facility Unavailable |
| Santa Cruz-Watsonville | Office $596.91 | Facility Unavailable |
| Santa Maria-Santa Barbara | Office $575.44 | Facility Unavailable |
| Santa Rosa-Petaluma | Office $603.17 | Facility Unavailable |
| Stockton | Office $543.68 | Facility Unavailable |
| Vallejo | Office $644.59 | Facility Unavailable |
| Visalia | Office $543.68 | Facility Unavailable |
| Yuba City | Office $543.68 | Facility Unavailable |
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91035 billing questions
How does 91035 differ from 91034?
91035 is for pH monitoring with a mucosa-attached wireless electrode. 91034 describes catheter-based esophageal pH monitoring.
Does 91035 include electrode placement and study interpretation?
Yes. The service includes placement of the mucosa-attached electrode, recording, analysis, and interpretation.
Can the professional and technical portions be billed separately?
Yes. Use modifier 26 for the professional interpretation and modifier TC for the technical service; billing without either modifier represents the global service.
Can modifier 50 be reported?
No. Modifier 50 is inappropriate for this service because its descriptor and anatomy do not support bilateral adjustment.
What documentation supports reporting 91035?
Document the reason for reflux testing, the wireless mucosa-attached method, the recorded study, and the interpretation of the results.
Can an assistant surgeon or co-surgeon be reported?
Assistant-at-surgery payment requires documentation of medical necessity. 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 indices and the applicable conversion factor. Unavailable or separately priced services are labeled rather than assigned a made-up amount.
Source: RVU26D. Effective 2026-10-01 through the day before 2027-01-01.
11,60391034,,Gastroesophageal reflux test,A,,0.95,5.03,,5.03,NA,0.08,6.06,6.06,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,60491034,26,Gastroesophageal reflux test,A,,0.95,0.50,,0.50,,0.06,1.51,1.51,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,60591034,TC,Gastroesophageal reflux test,A,,0.00,4.53,,4.53,NA,0.02,4.55,4.55,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,02,0,99,0.00,0.00,0.00
11,60691035,,G-esoph reflx tst w/electrod,A,,1.55,13.34,,13.34,NA,0.15,15.04,15.04,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,60791035,26,G-esoph reflx tst w/electrod,A,,1.55,0.87,,0.87,,0.13,2.55,2.55,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,60891035,TC,G-esoph reflx tst w/electrod,A,,0.00,12.47,,12.47,NA,0.02,12.49,12.49,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,02,0,99,0.00,0.00,0.00
11,60991037,,Esoph imped function test,A,,0.95,4.59,,4.59,NA,0.07,5.61,5.61,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00