CPT code 91038: Esophageal impedance, more than one hour2026 Medicare rate & RVUs in Georgia
Reports prolonged catheter-based esophageal impedance monitoring to evaluate reflux episodes and their relationship to symptoms during a recording lasting more than one hour.
Medicare pays $402.51–$453.05 for 91038 in the office in Georgia, from Rest of Georgia to Atlanta, GA. 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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On this page 9 sections
What 91038 covers
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.
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 91038 pays more and less in Georgia
| Payment locality | Office | Facility |
|---|---|---|
| Atlanta, GA | $453.05 | Unavailable |
| Rest of Georgia | $402.51 | Unavailable |
How the 91038 rate is calculated
Each of 91038’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 · 91038
RVUs × geographic indexes × conversion factor
Work1.10
1.10 RVUs× 1.000 GPCI
Practice expense12.17
12.17 RVUs× 1.000 GPCI
Malpractice0.08
0.08 RVUs× 1.000 GPCI
Adjusted RVUs
13.3500
Conversion factor
$33.4009
Medicare rate
$445.90
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 91038
The CMS indicators that decide how 91038 is paid alongside other services.
CMS payment indicators · 91038
Esophageal impedance, more than one hour
| 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 | 1 | Diagnostic test with separate professional (26) and technical (TC) components. |
What modifiers do to the payment
Modifier 26 · payment effect
With and without the modifier
91038 without 26 · national office
$445.90
Esophageal impedance, more than one hour
91038-26 · Professional component
$59.79
Pays only the interpretation and report.
91038 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 91037Esophageal impedanceOne hour or less
- Both report esophageal impedance testing; choose 91038 when the recording exceeds one hour and 91037 for the shorter-duration service.
- 91034Reflux monitoringNasal catheter pH test
- 91034 measures esophageal acidity with a catheter. This code reports prolonged impedance monitoring, which detects movement of material through the esophagus.
- 91035Reflux testingMucosa-attached telemetry electrode
- 91035 uses a wireless pH electrode for reflux monitoring. This code reports catheter-based impedance monitoring.
- 91010Esophageal manometryStandard pressure study
- 91010 evaluates esophageal motility with manometry. This code evaluates reflux-related events with impedance monitoring.
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 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.
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