Colonoscopy is a frequently used procedure in gastroenterology. It serves both diagnostic and preventive purposes. The procedure helps doctors detect everything from polyps to colorectal cancer. Among the various colonoscopy procedure codes, CPT code 45378 is a little tricky to bill.
That is why our billing experts at MediBillMD have compiled this comprehensive guide on CPT code 45378. We will walk you through what this code indicates, when to use it, its modifiers, and how to ensure its proper reimbursement. So, let’s start.
CPT Code 45378 – Description
CPT code 45378 refers to a diagnostic colonoscopy. Colonoscopy is a procedure in which a colonoscope (flexible tube with a camera) is inserted through the rectum to examine the colon and rectum for abnormalities. It is an effective and frequently used procedure for diagnosing inflammation, bleeding, or cancer in the colon.
The official definition of 45378, as described by the American Medical Association (AMA), is:
Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure).
An essential point that all billers must note is that CPT code 45378 not only covers the colonoscopy but also includes collecting specimens (biopsies or polypectomy) by brushing or washing.
We have discussed what 45378 represents. However, an important question arises here: What is a colonoscopy? Well, for a procedure to be considered a colonoscopy, the examination must reach the cecum (or enterocolic anastomosis if the cecum has been removed surgically). If the examination does not reach the cecum, different coding rules apply.
A common mistake that many billers make while filing 45378 is to confuse the usage requirements. Please note that code 45378 is not for screening colonoscopies (those routine checks for healthy individuals). The code is exclusively for diagnostic purposes.
Scenarios Where CPT Code 45378 is Applicable
So, when should you report CPT code 45378? In summary, it is all about medical necessity. The following are some real-world scenarios in which 45378 can be used:
Symptomatic Patients
Since 45378 is used for diagnostic colonoscopies, its most obvious use is for patients already showing symptoms of relevant diseases. For instance, if someone is experiencing abdominal pain, rectal bleeding, chronic diarrhea, or unexplained weight loss, a diagnostic colonoscopy might be ordered.
Follow-up on Abnormal Tests
If a patient shows an abnormal CT scan or a positive fecal occult blood test, it may signal a severe underlying issue. In this scenario, the physician may order a diagnostic colonoscopy.
High-Risk Surveillance
For patients with a history of polyps, colorectal cancer, or inflammatory bowel disease who require more frequent examinations than the standard ten-year interval, CPT code 45378 may be used for surveillance colonoscopies.
Applicable Modifiers for CPT Code 45378
You may append the following modifiers to code 45378.
| Modifier | Description |
|---|---|
| Modifier 22 | When a colonoscopy procedure is unusual or difficult and requires significantly more work. |
| Modifier 33 | For preventive services. If a colonoscopy starts as a screening but turns diagnostic, this ensures it is still covered as preventive for commercial plans. |
| Modifier PT | Similar to 33, but for Medicare patients only, flagging a screening colonoscopy that becomes diagnostic. |
| Modifier 52 | Applies when the procedure is reduced but not aborted. For example, the scope cannot reach the entire colon. |
Using the correct modifier is not enough. You also have to use the right modifier sequence for proper reimbursement. When using multiple modifiers, the modifier that most directly affects the reimbursement rate should be listed first.
For example, 45378-52-33 for a reduced screening colonoscopy.
CPT Code 45378 – Billing & Reimbursement Guidelines
CPT code 45378 is difficult to bill. There are a lot of details that must be accurately provided for proper reimbursement. The following guidelines will help ensure accurate billing and optimal reimbursement.
Patient Responsibility
When a colonoscopy begins as screening but becomes diagnostic (e.g., polyp removal), Medicare waives the deductible but requires coinsurance from the patient. However, this requirement is changing thanks to the recent changes in policy. In 2023-2026, the patient responsibility is 15%. By 2030, no coinsurance will be applicable.
Follow-up Colonoscopies
For Medicare beneficiaries with a positive result from non-invasive stool-based tests, the follow-up colonoscopy is now treated as a screening test rather than a diagnostic test (effective January 1, 2023), removing additional financial obligations for the patient.
Diagnosis Coding Requirements
Since CPT code 45378 is used for diagnostic purposes rather than screening, it requires a valid reason with a proper diagnostic code for reimbursement. If you fail to provide a diagnostic code, your claim will be denied. Some commonly used ICD-10 diagnostic codes with 45378 are:
- R19.5: Fecal abnormalities
- K92.2: Gastrointestinal hemorrhage, unspecified
- R10.31: Right lower quadrant pain
- K59.1: Functional diarrhea
Documentation Requirements
Documentation is the most crucial part of your claims. Incomplete documentation will undeniably result in a claim rejection. For CPT code 45378, make sure to include the following documents:
- Patient’s age, risk factors, family history, symptoms, and previous test results
- Maximum depth of penetration
- Description of bowel preparation quality
- Sedation details (if applicable)
- Technique used
- Patient tolerance of the procedure
- Detailed description of any abnormalities
- Location of findings (using specific anatomical landmarks)
- Size of lesions or polyps
- Appearance of abnormalities
- Any specimens that were collected or procedures performed
Wrapping Up
CPT code 45378 is an important code for billing diagnostic colonoscopies. As we have explored throughout this guide, proper coding, documentation, and modifier usage are important to avoid claim denials.
Key takeaways from our discussion include:
- Code Definition: CPT code 45378 represents a diagnostic flexible colonoscopy that reaches the cecum, with or without specimen collection by brushing or washing.
- Application: This code is only applicable for diagnostic procedures.
- Payer Differences: Medicare and commercial insurers have distinct requirements for colonoscopy coding.
If you are facing difficulty filing claims or your practice has been dealing with frequent denials, rest assured, our expert consultants at MediBillMD can provide the best gastroenterology billing services.
