CPT Coding for Gastric Emptying Imaging Studies Made Easy

Last Updated on August 7, 2025 by admin

Gastric emptying studies remain a vital tool in GI diagnostics however choosing the correct CPT code can be complex, even in 2025. This guide is designed to simplify the process by breaking down the procedure, the relevant codes, and how to avoid coding errors.

Even now in 2025, many practices are still navigating the differences between the codes and how they apply in different scenarios. And that’s completely understandable as these codes aren’t as straightforward as they seem.

This breakdown is here to help.

What a Gastric Emptying Study Actually Does

Gastric emptying studies evaluate how quickly the stomach empties its contents. Typically used when patients report bloating, nausea or unexplained upper GI discomfort. This scan gives doctors that insight without any invasive steps.

A radiolabeled meal (e.g., eggs or oatmeal with a radioactive tracer) is consumed and Imaging is performed at regular intervals to track digestion and movement through the GI tract.

For Healthcare providers this test is a staple in GI Specialty Care to diagnose conditions like gastroparesis and dumping syndrome that causes other digestive symptoms.

Understanding the Codes

If you’ve looked at these before, you’ve probably noticed how similar they sound. But they’re not interchangeable. The code you pick depends on which parts of the GI tract are being imaged, and how long the study takes. It’s more about the protocol than the symptoms.

Here’s a quick layout of the three main CPT codes:

CPT Code	SITE	Imaging Duration
78264	Stomach only	≤ 4 hours
78265	Stomach + Small Bowel	~24–26 hours
78266	Stomach + Small Bowel + Colon	Multi-day (up to 3 days)

Let’s walk through each one, with the focus on when and how they’re used.

CPT 78264 – For Short, Stomach-Only Studies

This is the code for a basic gastric emptying scan. If the focus is just on the stomach and imaging ends within 4 hours, this is the one to use. It works whether the patient consumed solids, liquids, or both.

It’s one of the more common codes, but it’s also easy to use incorrectly. Even if the study involves both solid and liquid phases, if they’re done on the same day as part of the same protocol, it’s still coded just once using 78264.

CPT 78265 – When Small Bowel Transit is Included

Sometimes, doctors want to know how food moves through the small intestine, not just the stomach. This is usually when they suspect that delayed motility may extend further down the GI tract. That’s where 78265 comes in.

The study takes longer. Imaging can happen across a 24 to 26-hour window. If the report mentions small bowel transit, or shows food progression past the stomach into the intestines, this is likely the correct code. But that part must be documented clearly to support this code.

CPT 78266 – Multi-Day, Full GI Transit

This is the most detailed scan in this group. It’s not just the stomach and small bowel, it includes colon transit too. These are long studies, sometimes spanning two to three days. Providers use them when there’s concern about a broader motility disorder that requires advanced radiological imaging

Because it’s multi-day, there’s a chance it’ll be mistaken as two procedures. But it’s still just one study, so it should be coded once, with the correct documentation showing duration and regions imaged.

ICD-10 Codes: Appropriate ICD-10 codes, such as K31.84 (Gastroparesis), R11.2 (Nausea with vomiting), or R10.13 (Epigastric pain), should be linked to the CPT code to define the condition and support medical necessity

What If the Scan Happens on Two Different Days?

There are cases where a solid phase study is done first, and then, a few days later, a liquid phase study is added. Maybe the doctor needed more information. Or maybe the patient’s symptoms didn’t improve, and they wanted a follow-up.

Here’s what matters:
If both studies were part of the original plan, code it once.
If the second study was added later, with a different clinical reason and different date, it might be coded separately.

This isn’t common, but it happens. And when it does, the documentation has to explain it clearly. Without that, billing both will often lead to denials.

Common Issues That Still Show Up in 2025

Even with years of clarification, we still see claims denied due to common medical coding errors. It usually comes down to mismatches between codes and documentation. Here are a few things to watch for:

Reporting 78265 When the Report Only Shows Stomach Imaging (78265 vs78264). CPT 78265 is intended for gastric emptying studies with small bowel transit and if the imaging is limited to the stomach only, then 78264 is the correct code. So, review the imaging scope in the report and if small bowel transit is not assessed or documented, change the code to 78264 to reflect the actual procedure.
Billing 78264 Twice on the Same Day for Solid + Liquid Phases. CPT 78264 should not be billed twice for dual-phase studies performed on the same day.: AMA guidance states that dual-phase protocols (solid + liquid) are considered a single study. Report 78264 once for both phases if performed together and if solid and liquid studies are done on separate days, then 78264 may be billed separately per date of service.
Using 78266 But Not Mentioning Colon Transit in the Notes. CPT 78266 includes small bowel and colon transit over multiple days and if colon transit is not documented, the code is not supported. So, ensure the report explicitly mentions colon imaging and transit assessment and if colon transit is missing, downgrade to 78265 (small bowel only) or 78264 (stomach only) depending on scope.
Duration Inconsistencies: Using 78265 for a 2-Hour Scan. CPT 78265 typically involves imaging over 24–26 hours to assess small bowel transit. A 2-hour scan is insufficient to evaluate small bowel transit. So, if imaging is limited to 2 hours and only the stomach is assessed, use 78264 and for small bowel transit, ensure the scan duration and intervals meet the criteria for 78265.

If the code doesn’t match the scan length or the regions evaluated, it’ll get flagged.

CPT Assistant Can Really Help Here

If there’s ever any doubt, the AMA’s CPT Assistant articles are worth checking. They’ve offered solid guidance over the years – especially for scenarios like dual-phase studies, separate dates of service, and what qualifies as small bowel or colon transit.

These clarifications are especially helpful when you’re dealing with payers who are strict about documentation, or if you’re preparing an appeal.

Do not confuse gastric emptying scans (nuclear medicine) with Esophageal manometry and Antroduodenal manometry. These are catheter-based motility studies, measuring pressure, not movement, and have entirely different CPT codes.

Different tools, different methods, different CPT codes. Make sure the procedure being coded actually involved imaging.

Documentation Is Still the Key

By now, most imaging centers are using templates. That’s good. But templates don’t always include everything. For gastric emptying studies, here’s what should be mentioned clearly:

Length of the imaging (e.g., 4 hours vs. 24 hours)
Which parts of the GI tract were evaluated
If small bowel or colon transit was assessed
If there were multiple sessions or different dates
The type of meal (solid, liquid, or both)

That’s what supports the CPT code being billed. Without it, even the right code could be denied.

Appropriate Modifiers Usage:

Correct modifier application ensures accurate claims submission, prevents denials, and reflects the exact circumstances of a procedure. Below are examples of commonly used modifiers in gastric emptying studies and related nuclear medicine procedures.

Modifier 59: CPT Code 78264 – (Gastric emptying study) Modifier 59 – (Distinct procedural service) CPT Code 78227 – (Hepatobiliary scan)
Modifier 76 or 77: A patient visits the hospital for a gastric emptying study to diagnose a motility disorder. After receiving immediate treatment, the same physician conducts another gastric emptying study later in the day to confirm the effectiveness of the treatment.
Modifier 91: A patient undergoes an initial gastric emptying study early in the morning. Due to the patient’s symptoms and to gauge the impact of different meals, the physician orders repeat gastric emptying studies after lunch and dinner.
Modifier 52: Reduced service: e.g., partial imaging due to patient intolerance
Modifier 53: Discontinued procedure: if study could not be completed due to patient factors