$201.55–$257.55
Both report esophageal impedance testing; choose 91038 when the recording exceeds one hour and 91037 for the shorter-duration service.
On this page
CMS RVU26D · Effective 2026-10-01
91038 Esophageal impedance Medicare reimbursement rates in California
Reports prolonged catheter-based esophageal impedance monitoring to evaluate reflux episodes and their relationship to symptoms during a recording lasting more than one hour. Compare 91038 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 91038 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
$484.31–$628.37
29 of 29 localities have a supported rate.
Lowest: Chico
Highest: San Jose-Sunnyvale-Santa Clara (San Benito Cnty)
A spread of $144.06 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 91038 pays more and less in California
29 payment localities
$484.31 to $628.37
Gastroenterology testing
About 91038: Prolonged esophageal impedance monitoring
Reports prolonged catheter-based esophageal impedance monitoring to evaluate reflux episodes and their relationship to symptoms during a recording lasting more than one hour.
A thin catheter with impedance sensors is passed through the nose into the esophagus to record movement of swallowed material and reflux over a prolonged period. The test can help evaluate persistent heartburn, regurgitation, or other suspected reflux symptoms, including symptoms that continue during acid-suppressing treatment. It is typically performed in a gastroenterology or motility laboratory, with a physician interpreting the recording and reporting the findings.
Select this service for impedance monitoring lasting more than one hour, rather than the shorter-duration service. Documentation should support catheter placement, the recording period, analysis, and interpretation. CMS recognizes professional and technical components: modifier 26 identifies interpretation, modifier TC identifies equipment and staff, and no component modifier represents the global service. The 0-day global period includes same-day preoperative and postoperative care. Modifier 50 is inappropriate. Assistant-at-surgery payment requires documented medical necessity; co-surgeons and team surgery are not permitted.
CMS billing rules for 91038
- 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 RVU1.10 · 8%
- Practice expense (office) RVU12.17 · 91%
- Malpractice RVU0.08 · 1%
3.6K
Medicare services in 2024 · #2063 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.
91038 compared with similar codes
Office rates for California, from the same CMS release.
$217.84–$278.92
91034 measures esophageal acidity with a catheter. This code reports prolonged impedance monitoring, which detects movement of material through the esophagus.
$543.68–$702.66
91035 uses a wireless pH electrode for reflux monitoring. This code reports catheter-based impedance monitoring.
$264.45–$337.90
91010 evaluates esophageal motility with manometry. This code evaluates reflux-related events with impedance monitoring.
Compare 91038 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 $484.58 | Facility Unavailable |
| Chico | Office $484.31 | Facility Unavailable |
| El Centro | Office $484.32 | Facility Unavailable |
| Fresno | Office $484.31 | Facility Unavailable |
| Hanford-Corcoran | Office $484.31 | Facility Unavailable |
| Los Angeles-Long Beach-Anaheim (Los Angeles/Orange Cnty) | Office $520.90 | Facility Unavailable |
| Madera | Office $484.31 | Facility Unavailable |
| Merced | Office $484.31 | Facility Unavailable |
| Modesto | Office $484.31 | Facility Unavailable |
| Napa | Office $576.17 | Facility Unavailable |
| Oxnard-Thousand Oaks-Ventura | Office $519.90 | Facility Unavailable |
| Redding | Office $484.31 | Facility Unavailable |
| Rest Of California | Office $484.31 | Facility Unavailable |
| Riverside-San Bernardino-Ontario | Office $485.19 | Facility Unavailable |
| Sacramento-Roseville-Folsom | Office $512.24 | Facility Unavailable |
| Salinas | Office $510.43 | Facility Unavailable |
| San Diego-Chula Vista-Carlsbad | Office $525.45 | Facility Unavailable |
| San Francisco-Oakland-Berkeley (Marin Cnty) | Office $614.61 | Facility Unavailable |
| San Francisco-Oakland-Berkeley (San Francisco/San Mateo/Alameda/Contra Costa Cnty) | Office $614.52 | Facility Unavailable |
| San Jose-Sunnyvale-Santa Clara (San Benito Cnty) | Office $628.37 | Facility Unavailable |
| San Jose-Sunnyvale-Santa Clara (Santa Clara Cnty) | Office $628.00 | Facility Unavailable |
| San Luis Obispo-Paso Robles | Office $501.79 | Facility Unavailable |
| Santa Cruz-Watsonville | Office $532.83 | Facility Unavailable |
| Santa Maria-Santa Barbara | Office $513.17 | Facility Unavailable |
| Santa Rosa-Petaluma | Office $538.44 | Facility Unavailable |
| Stockton | Office $484.31 | Facility Unavailable |
| Vallejo | Office $576.03 | Facility Unavailable |
| Visalia | Office $484.31 | Facility Unavailable |
| Yuba City | Office $484.31 | Facility Unavailable |
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91038 billing questions
When should this code be selected instead of 91037?
Use this code when the impedance recording lasts more than one hour. Code 91037 is for the shorter-duration impedance test.
Can the professional and technical services be billed separately?
Yes. Modifier 26 identifies the professional interpretation, and modifier TC identifies the technical service, including equipment and staff. Without either modifier, the claim represents the global service.
What documentation supports the service?
Document catheter placement, the duration of the impedance recording, and the analysis and interpretation. The record should also support the clinical reason for evaluating reflux or related symptoms.
Is modifier 50 appropriate for this test?
No. CMS identifies bilateral adjustment as inappropriate for this service.
How does this differ from catheter-based pH monitoring?
Impedance monitoring evaluates movement of material through the esophagus, including reflux episodes. Code 91034 describes catheter-based pH monitoring, which measures esophageal acidity.
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.
11,60991037,,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
11,61091037,26,Esoph imped function test,A,,0.95,0.54,,0.54,,0.05,1.54,1.54,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,61191037,TC,Esoph imped function test,A,,0.00,4.05,,4.05,NA,0.02,4.07,4.07,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,02,0,99,0.00,0.00,0.00
11,61291038,,Esoph imped funct test > 1hr,A,,1.10,12.17,,12.17,NA,0.08,13.35,13.35,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,61391038,26,Esoph imped funct test > 1hr,A,,1.10,0.63,,0.63,,0.06,1.79,1.79,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00
11,61491038,TC,Esoph imped funct test > 1hr,A,,0.00,11.54,,11.54,NA,0.02,11.56,11.56,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,02,0,99,0.00,0.00,0.00
11,61591040,,Esoph balloon distension tst,A,,0.95,16.24,,16.24,NA,0.08,17.27,17.27,1,000,0.00,0.00,0.00,0,0,0,0,0,9,,33.4009,09,0,99,0.00,0.00,0.00