Electrogastrography recording of stomach electrical activity done together with a provocative challenge such as a water load or test meal.
- Medicare
- $508.36
- Work RVU
- 0.64
- Global, days
- Region
- Other
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 2 cited references ↓
- GI symptom history
- Type and volume of provocative challenge
- Baseline and post-challenge recording results
- Prior gastric emptying or motility testing
- Interpretation by the reading physician
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 2 cited references ↓
91133 is electrogastrography with provocative testing. The baseline recording is taken, then the patient drinks water or eats a test meal and the recording continues to show how the stomach's rhythm responds. It is a gastroenterology motility study.
Orthopedic practices do not perform or bill it. The tie to ortho is the patient population. Long opioid courses after spine fusion or joint replacement can slow gastric emptying, and diabetic foot patients may already carry a gastroparesis diagnosis. When those patients report persistent nausea or early fullness during an ortho visit, the clinic documents it and refers.
For billing, 91133 replaces 91132 when a provocation is done. It is not billed in addition. It splits into professional and technical components with modifiers 26 and TC. Commercial coverage is thin, with many payers treating the test as investigational, so authorization and a documented prior gastric emptying study improve the odds of payment.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
Work RVU vs. total RVU
The work RVU (0.64) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (15.22) adds practice overhead and malpractice, and is what drives the Medicare payment below.
| Work RVU | 0.64 |
| Practice expense RVU | 14.55 |
| Malpractice RVU | 0.03 |
| Total RVU | 15.22 |
| Medicare national rate | $508.36 |
| Global period | days |
Payment by site of service
Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.
Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026
| Setting | Medicare rate (national) |
|---|---|
Office (PFS non-facility) Procedure performed in physician's office | $508.36 |
HOPD (APC 5734) Hospital outpatient department | $135.93 |
Common denial reasons
The recurring reasons claims for CPT 91133 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Billed together with 91132
- Payer considers the test investigational
- No prior authorization
- Provocative challenge not documented
- Component billing conflict with facility
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 2 cited references ↓
01Can 91132 and 91133 be billed on the same day?
02What counts as provocative testing for 91133?
03Why would an orthopedic patient need electrogastrography?
Sources & references
Editorial content was developed using the following public sources.
- 01CMS Physician Fee Schedule 2026
- 02cms.govhttps://www.cms.gov/medicare/payment/fee-schedules/physician
Mira Scribe
Mira Scribe captures GI complaints and opioid use patients mention in follow-up visits, so the referral note to gastroenterology is complete.
See how Mira captures CPT 91133 documentation