Diagnostic colonoscopy

What is CPT Code 45378?

Diagnostic colonoscopy — insertion of a flexible scope through the rectum to visualize the entire colon. Used for colorectal cancer screening, evaluation of rectal bleeding, and surveillance after polyp removal.

The Medicare reimbursement rate shown above is the amount the federal government has determined is a reasonable payment for this service. Hospitals and providers that participate in Medicare have agreed to accept these rates from Medicare patients.

Who typically bills this:Gastroenterologist + facility (ASC or hospital)

Common Billing Errors for CPT 45378

• !Screening colonoscopy billed as diagnostic (higher cost-sharing for patient) when no symptoms were present
• !45378 billed alongside a biopsy or polypectomy code (45380 or 45385) — the add-on procedure code replaces 45378
• !Anesthesia billed for procedures where moderate sedation is the standard and already bundled

Red Flags on Your Bill

Negotiation Tips for CPT 45378

1. 1If this was a routine screening colonoscopy, confirm it was coded as screening (G0105 or G0121 for Medicare) vs diagnostic — it affects your cost-sharing
2. 2If polyps were removed, the correct code is 45385, not 45378 — verify your Explanation of Benefits
3. 3ASC facility fees for colonoscopy are typically $400–$800 vs $1,500–$3,000 at a hospital outpatient department

Codes That Often Appear With This One

These CPT codes commonly appear on the same bill. Review each one to spot potential bundling errors or duplicate charges.

Found CPT 45378 on Your Bill?

If you see CPT code 45378 on a hospital or medical bill, compare the charged amount to the Medicare rate above. If your bill shows a significantly higher charge, you may have grounds to negotiate.

1. Note the amount charged for CPT 45378 on your itemized bill
2. Compare it to the Medicare rate above — calculate the markup
3. Call the billing department and use the Medicare rate as your anchor:“I see CPT code 45378 billed at [amount]. The Medicare rate for this procedure is $342.86. I'd like to discuss a fair adjustment.”