CPT Code 77066 — What It Means and What Medicare Pays
CPT code · Imaging · Typically billed in: Imaging center or hospital
Seeing CPT code 77066 on your medical bill?
This code is only one part of the picture — your bill, EOB, insurance adjustments, units, and other charges may affect what you actually owe. MD Bill Check reads the codes on your document, checks the bill in context, and flags items that may be worth reviewing.
What Medicare pays for CPT code 77066
Medicare national average (2025): $153.65
Treat this as a reference point, not a ceiling. It is what Medicare pays nationally before any local adjustment — private insurers negotiate their own rates, and a hospital's list price for the same code is often several times higher. A charge far above this number is not automatically an error, but it is a fair thing to ask about.
How many units of CPT code 77066 should appear on one day
If your bill shows more units of CPT code 77066 for a single date of service than that, it is worth asking the billing office to explain the count — duplicate lines and unit-entry mistakes are among the most common medical-billing errors.
Codes normally billed as one with CPT code 77066
Medicare's National Correct Coding Initiative (NCCI) publishes pairs of codes that are considered a single service when performed together. Billing them separately — "unbundling" — inflates a bill.
| Paired code | How the pair is normally treated |
|---|---|
| 77065 Imaging | Not separately payable — the pair is expected to be billed as one service |
| 77067 Imaging | Separately payable only when a modifier documents a genuinely distinct service |
Seeing one of these codes billed alongside CPT code 77066 is not proof of an error — a modifier can legitimately justify it — but it is a specific, answerable question to put to the billing office. What unbundling means, and how to raise it.
Related codes
Keep reviewing your bill
- How to Check a Medical Bill for Errors Before You Pay
- Medical Bill vs EOB: What Is the Difference?
- What Is an Itemized Medical Bill? How to Request One
- Denial and remark codes explained (CARC & RARC)
Frequently asked questions about CPT code 77066
What does CPT code 77066 mean on a medical bill?
Diagnostic mammogram of both breasts. Bills group it under "Imaging", and it is typically provided in this setting: Imaging center or hospital.
How much does CPT code 77066 cost?
Medicare's 2025 national average payment for CPT code 77066 is $153.65. That figure is a public Medicare benchmark, not a cap on what a provider may charge you — commercial insurers negotiate their own rates and hospital list prices are often several times higher.
How many units of CPT code 77066 can be billed per day?
Medicare's Medically Unlikely Edits normally expect at most 1 unit of CPT code 77066 per patient per day. This is an absolute policy limit — more than 1 unit a day is not payable under any circumstances.
Not sure this charge belongs on your bill?
Upload the bill — MD Bill Check reads the codes on your document, checks the bill in context, and flags items that may be worth reviewing. Free, no account needed.