What's a fair price for CPT 45378?

Most patients should expect to pay no more than 2–3× the Medicare allowable for the same service. Medicare's allowable rate for 45378 is roughly $390, which is a useful fair-price anchor. A reasonable target when negotiating cash-pay or self-pay is somewhere between the Medicare rate and the in-network allowed amount your insurer would pay.

How do I dispute CPT 45378?

Request a fully itemized bill with CPT codes and your EOB. For 45378 specifically, the most common issues are preventive vs diagnostic, anesthesia. Call the provider's billing office and dispute the specific line items you're contesting, with the reason for each; federal and state law require them to investigate and pause collections while the dispute is open. Or upload the bill to patientbill.org and we'll generate a word-for-word call script for you — completely free.

Why is CPT 45378 on my bill?

Colonoscopy, diagnostic. It appears on bills when a service was performed in a hospital outpatient or asc setting and the provider documented enough work to support this specific code. If the description doesn't match what you remember happening at your visit, ask for the chart note that supports the code.

CPT code

45378 — Colonoscopy, diagnostic

Plain-English reference for CPT 45378. What it covers, what it typically costs, and the billing errors patientbill.org looks for on this code.

Typical setting: Hospital outpatient or ASC
Medicare allowable: $390
Common private-payer range: $1,000 – $5,000

The Medicare allowable is the national non-facility rate from the CMS Physician Fee Schedule and is the most defensible "fair price" anchor. Commercial charges typically run 2–5× this number; hospital list prices can be much higher still.

What this code actually is

CPT 45378 is a diagnostic colonoscopy. The same procedure is coded G0121 or 45380–45385 when performed as preventive screening; only diagnostic colonoscopies have patient cost-sharing. If your colonoscopy was a routine screening and got re-coded to 45378 because a polyp was removed, federal rules still require it to be covered as preventive — this is one of the most disputable bills in healthcare.

Audit issues we look for on 45378

Preventive vs diagnostic re-coding — screening turned into a diagnostic charge
Anesthesia surprises — sedation billed by an out-of-network provider on an in-network procedure

Think your bill has the wrong 45378 charge?

Upload the bill and we'll check for upcoding, unbundling, duplicates, and prices above what's reasonable. PatientBill is 100% free — no fees, ever. You keep every dollar we save you.

Common questions about CPT 45378

Private-payer charges typically fall in the $1,000 – $5,000 range, though hospital list prices can run much higher. Medicare's allowable rate for 45378 is roughly $390, which is a useful fair-price anchor. If your bill for this code is significantly above the high end of that range, ask for an itemized statement and compare against your Explanation of Benefits (EOB) — the insurance "allowed amount" is the most defensible reference point.

Related codes in Minor procedures & surgery

Patientbill.org is not affiliated with any provider, insurer, or the AMA. Code descriptions are CMS-published short descriptors plus our own plain-English explanations; pricing references are from the CMS Medicare Physician Fee Schedule and public charge benchmarks and may be outdated. Verify your specific charges against your EOB.